diff --git a/aconfig/init.go b/aconfig/init.go
index 256b213..de155ab 100644
--- a/aconfig/init.go
+++ b/aconfig/init.go
@@ -47,7 +47,7 @@
 	// For create-device-config-sysprops: Generate aconfig flag value map text file
 	aconfigTextRule = pctx.AndroidStaticRule("aconfig_text",
 		blueprint.RuleParams{
-			Command: `${aconfig} dump-cache --dedup --format='{fully_qualified_name}={state:bool}'` +
+			Command: `${aconfig} dump-cache --dedup --format='{fully_qualified_name}:{permission}={state:bool}'` +
 				` --cache ${in}` +
 				` --out ${out}.tmp` +
 				` && ( if cmp -s ${out}.tmp ${out} ; then rm ${out}.tmp ; else mv ${out}.tmp ${out} ; fi )`,
diff --git a/android/Android.bp b/android/Android.bp
index 3c38148..774d24a 100644
--- a/android/Android.bp
+++ b/android/Android.bp
@@ -42,6 +42,7 @@
         "buildinfo_prop.go",
         "compliance_metadata.go",
         "config.go",
+        "container.go",
         "test_config.go",
         "configurable_properties.go",
         "configured_jars.go",
diff --git a/android/arch.go b/android/arch.go
index e0c6908..6d896e5 100644
--- a/android/arch.go
+++ b/android/arch.go
@@ -19,6 +19,7 @@
 	"fmt"
 	"reflect"
 	"runtime"
+	"slices"
 	"strings"
 
 	"github.com/google/blueprint"
@@ -587,19 +588,21 @@
 	}
 
 	osTargets := mctx.Config().Targets[os]
+
 	image := base.commonProperties.ImageVariation
 	// Filter NativeBridge targets unless they are explicitly supported.
 	// Skip creating native bridge variants for non-core modules.
 	if os == Android && !(base.IsNativeBridgeSupported() && image == CoreVariation) {
+		osTargets = slices.DeleteFunc(slices.Clone(osTargets), func(t Target) bool {
+			return bool(t.NativeBridge)
+		})
+	}
 
-		var targets []Target
-		for _, t := range osTargets {
-			if !t.NativeBridge {
-				targets = append(targets, t)
-			}
-		}
-
-		osTargets = targets
+	// Filter HostCross targets if disabled.
+	if base.HostSupported() && !base.HostCrossSupported() {
+		osTargets = slices.DeleteFunc(slices.Clone(osTargets), func(t Target) bool {
+			return t.HostCross
+		})
 	}
 
 	// only the primary arch in the ramdisk / vendor_ramdisk / recovery partition
diff --git a/android/arch_test.go b/android/arch_test.go
index f0a58a9..6134a06 100644
--- a/android/arch_test.go
+++ b/android/arch_test.go
@@ -332,6 +332,12 @@
 		}
 
 		module {
+			name: "nohostcross",
+			host_supported: true,
+			host_cross_supported: false,
+		}
+
+		module {
 			name: "baz",
 			device_supported: false,
 		}
@@ -355,13 +361,14 @@
 	`
 
 	testCases := []struct {
-		name          string
-		preparer      FixturePreparer
-		fooVariants   []string
-		barVariants   []string
-		bazVariants   []string
-		quxVariants   []string
-		firstVariants []string
+		name                string
+		preparer            FixturePreparer
+		fooVariants         []string
+		barVariants         []string
+		noHostCrossVariants []string
+		bazVariants         []string
+		quxVariants         []string
+		firstVariants       []string
 
 		multiTargetVariants    []string
 		multiTargetVariantsMap map[string][]string
@@ -373,6 +380,7 @@
 			preparer:            nil,
 			fooVariants:         []string{"android_arm64_armv8-a", "android_arm_armv7-a-neon"},
 			barVariants:         append(buildOSVariants, "android_arm64_armv8-a", "android_arm_armv7-a-neon"),
+			noHostCrossVariants: append(buildOSVariants, "android_arm64_armv8-a", "android_arm_armv7-a-neon"),
 			bazVariants:         nil,
 			quxVariants:         append(buildOS32Variants, "android_arm_armv7-a-neon"),
 			firstVariants:       append(buildOS64Variants, "android_arm64_armv8-a"),
@@ -390,6 +398,7 @@
 			}),
 			fooVariants:         nil,
 			barVariants:         buildOSVariants,
+			noHostCrossVariants: buildOSVariants,
 			bazVariants:         nil,
 			quxVariants:         buildOS32Variants,
 			firstVariants:       buildOS64Variants,
@@ -406,6 +415,7 @@
 			}),
 			fooVariants:         []string{"android_arm64_armv8-a", "android_arm_armv7-a-neon"},
 			barVariants:         []string{"linux_musl_x86_64", "linux_musl_arm64", "linux_musl_x86", "android_arm64_armv8-a", "android_arm_armv7-a-neon"},
+			noHostCrossVariants: []string{"linux_musl_x86_64", "linux_musl_x86", "android_arm64_armv8-a", "android_arm_armv7-a-neon"},
 			bazVariants:         nil,
 			quxVariants:         []string{"linux_musl_x86", "android_arm_armv7-a-neon"},
 			firstVariants:       []string{"linux_musl_x86_64", "linux_musl_arm64", "android_arm64_armv8-a"},
@@ -461,6 +471,10 @@
 				t.Errorf("want bar variants:\n%q\ngot:\n%q\n", w, g)
 			}
 
+			if g, w := enabledVariants(ctx, "nohostcross"), tt.noHostCrossVariants; !reflect.DeepEqual(w, g) {
+				t.Errorf("want nohostcross variants:\n%q\ngot:\n%q\n", w, g)
+			}
+
 			if g, w := enabledVariants(ctx, "baz"), tt.bazVariants; !reflect.DeepEqual(w, g) {
 				t.Errorf("want baz variants:\n%q\ngot:\n%q\n", w, g)
 			}
diff --git a/android/container.go b/android/container.go
new file mode 100644
index 0000000..c4fdd9c
--- /dev/null
+++ b/android/container.go
@@ -0,0 +1,233 @@
+// Copyright 2024 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package android
+
+import (
+	"reflect"
+	"slices"
+
+	"github.com/google/blueprint"
+)
+
+type StubsAvailableModule interface {
+	IsStubsModule() bool
+}
+
+// Returns true if the dependency module is a stubs module
+var depIsStubsModule = func(_ ModuleContext, _, dep Module) bool {
+	if stubsModule, ok := dep.(StubsAvailableModule); ok {
+		return stubsModule.IsStubsModule()
+	}
+	return false
+}
+
+// Labels of exception functions, which are used to determine special dependencies that allow
+// otherwise restricted inter-container dependencies
+type exceptionHandleFuncLabel int
+
+const (
+	checkStubs exceptionHandleFuncLabel = iota
+)
+
+// Functions cannot be used as a value passed in providers, because functions are not
+// hashable. As a workaround, the exceptionHandleFunc enum values are passed using providers,
+// and the corresponding functions are called from this map.
+var exceptionHandleFunctionsTable = map[exceptionHandleFuncLabel]func(ModuleContext, Module, Module) bool{
+	checkStubs: depIsStubsModule,
+}
+
+type InstallableModule interface {
+	EnforceApiContainerChecks() bool
+}
+
+type restriction struct {
+	// container of the dependency
+	dependency *container
+
+	// Error message to be emitted to the user when the dependency meets this restriction
+	errorMessage string
+
+	// List of labels of allowed exception functions that allows bypassing this restriction.
+	// If any of the functions mapped to each labels returns true, this dependency would be
+	// considered allowed and an error will not be thrown.
+	allowedExceptions []exceptionHandleFuncLabel
+}
+type container struct {
+	// The name of the container i.e. partition, api domain
+	name string
+
+	// Map of dependency restricted containers.
+	restricted []restriction
+}
+
+var (
+	VendorContainer = &container{
+		name:       VendorVariation,
+		restricted: nil,
+	}
+	SystemContainer = &container{
+		name: "system",
+		restricted: []restriction{
+			{
+				dependency: VendorContainer,
+				errorMessage: "Module belonging to the system partition other than HALs is " +
+					"not allowed to depend on the vendor partition module, in order to support " +
+					"independent development/update cycles and to support the Generic System " +
+					"Image. Try depending on HALs, VNDK or AIDL instead.",
+				allowedExceptions: []exceptionHandleFuncLabel{},
+			},
+		},
+	}
+	ProductContainer = &container{
+		name: ProductVariation,
+		restricted: []restriction{
+			{
+				dependency: VendorContainer,
+				errorMessage: "Module belonging to the product partition is not allowed to " +
+					"depend on the vendor partition module, as this may lead to security " +
+					"vulnerabilities. Try depending on the HALs or utilize AIDL instead.",
+				allowedExceptions: []exceptionHandleFuncLabel{},
+			},
+		},
+	}
+	ApexContainer = initializeApexContainer()
+	CtsContainer  = &container{
+		name: "cts",
+		restricted: []restriction{
+			{
+				dependency: SystemContainer,
+				errorMessage: "CTS module should not depend on the modules belonging to the " +
+					"system partition, including \"framework\". Depending on the system " +
+					"partition may lead to disclosure of implementation details and regression " +
+					"due to API changes across platform versions. Try depending on the stubs instead.",
+				allowedExceptions: []exceptionHandleFuncLabel{checkStubs},
+			},
+		},
+	}
+)
+
+func initializeApexContainer() *container {
+	apexContainer := &container{
+		name: "apex",
+		restricted: []restriction{
+			{
+				dependency: SystemContainer,
+				errorMessage: "Module belonging to Apex(es) is not allowed to depend on the " +
+					"modules belonging to the system partition. Either statically depend on the " +
+					"module or convert the depending module to java_sdk_library and depend on " +
+					"the stubs.",
+				allowedExceptions: []exceptionHandleFuncLabel{checkStubs},
+			},
+		},
+	}
+
+	apexContainer.restricted = append(apexContainer.restricted, restriction{
+		dependency: apexContainer,
+		errorMessage: "Module belonging to Apex(es) is not allowed to depend on the " +
+			"modules belonging to other Apex(es). Either include the depending " +
+			"module in the Apex or convert the depending module to java_sdk_library " +
+			"and depend on its stubs.",
+		allowedExceptions: []exceptionHandleFuncLabel{checkStubs},
+	})
+
+	return apexContainer
+}
+
+type ContainersInfo struct {
+	belongingContainers []*container
+
+	belongingApexes []ApexInfo
+}
+
+func (c *ContainersInfo) BelongingContainers() []*container {
+	return c.belongingContainers
+}
+
+var ContainersInfoProvider = blueprint.NewProvider[ContainersInfo]()
+
+// Determines if the module can be installed in the system partition or not.
+// Logic is identical to that of modulePartition(...) defined in paths.go
+func installInSystemPartition(ctx ModuleContext) bool {
+	module := ctx.Module()
+	return !module.InstallInTestcases() &&
+		!module.InstallInData() &&
+		!module.InstallInRamdisk() &&
+		!module.InstallInVendorRamdisk() &&
+		!module.InstallInDebugRamdisk() &&
+		!module.InstallInRecovery() &&
+		!module.InstallInVendor() &&
+		!module.InstallInOdm() &&
+		!module.InstallInProduct() &&
+		determineModuleKind(module.base(), ctx.blueprintBaseModuleContext()) == platformModule
+}
+
+func generateContainerInfo(ctx ModuleContext) ContainersInfo {
+	inSystem := installInSystemPartition(ctx)
+	inProduct := ctx.Module().InstallInProduct()
+	inVendor := ctx.Module().InstallInVendor()
+	inCts := false
+	inApex := false
+
+	if m, ok := ctx.Module().(ImageInterface); ok {
+		inProduct = inProduct || m.ProductVariantNeeded(ctx)
+		inVendor = inVendor || m.VendorVariantNeeded(ctx)
+	}
+
+	props := ctx.Module().GetProperties()
+	for _, prop := range props {
+		val := reflect.ValueOf(prop).Elem()
+		if val.Kind() == reflect.Struct {
+			testSuites := val.FieldByName("Test_suites")
+			if testSuites.IsValid() && testSuites.Kind() == reflect.Slice && slices.Contains(testSuites.Interface().([]string), "cts") {
+				inCts = true
+			}
+		}
+	}
+
+	var belongingApexes []ApexInfo
+	if apexInfo, ok := ModuleProvider(ctx, AllApexInfoProvider); ok {
+		belongingApexes = apexInfo.ApexInfos
+		inApex = true
+	}
+
+	containers := []*container{}
+	if inSystem {
+		containers = append(containers, SystemContainer)
+	}
+	if inProduct {
+		containers = append(containers, ProductContainer)
+	}
+	if inVendor {
+		containers = append(containers, VendorContainer)
+	}
+	if inCts {
+		containers = append(containers, CtsContainer)
+	}
+	if inApex {
+		containers = append(containers, ApexContainer)
+	}
+
+	return ContainersInfo{
+		belongingContainers: containers,
+		belongingApexes:     belongingApexes,
+	}
+}
+
+func setContainerInfo(ctx ModuleContext) {
+	if _, ok := ctx.Module().(InstallableModule); ok {
+		containersInfo := generateContainerInfo(ctx)
+		SetProvider(ctx, ContainersInfoProvider, containersInfo)
+	}
+}
diff --git a/android/image.go b/android/image.go
index c278dcd..0f03107 100644
--- a/android/image.go
+++ b/android/image.go
@@ -22,7 +22,7 @@
 	// VendorVariantNeeded should return true if the module needs a vendor variant (installed on the vendor image).
 	VendorVariantNeeded(ctx BaseModuleContext) bool
 
-	// ProductVariantNeeded should return true if the module needs a product variant (unstalled on the product image).
+	// ProductVariantNeeded should return true if the module needs a product variant (installed on the product image).
 	ProductVariantNeeded(ctx BaseModuleContext) bool
 
 	// CoreVariantNeeded should return true if the module needs a core variant (installed on the system image).
diff --git a/android/module.go b/android/module.go
index 9f7cb37..91f2056 100644
--- a/android/module.go
+++ b/android/module.go
@@ -603,6 +603,11 @@
 	Device_supported *bool
 }
 
+type hostCrossProperties struct {
+	// If set to true, build a variant of the module for the host cross.  Defaults to true.
+	Host_cross_supported *bool
+}
+
 type Multilib string
 
 const (
@@ -718,6 +723,10 @@
 		m.AddProperties(&base.hostAndDeviceProperties)
 	}
 
+	if hod&hostCrossSupported != 0 {
+		m.AddProperties(&base.hostCrossProperties)
+	}
+
 	initArchModule(m)
 }
 
@@ -803,6 +812,7 @@
 	distProperties          distProperties
 	variableProperties      interface{}
 	hostAndDeviceProperties hostAndDeviceProperties
+	hostCrossProperties     hostCrossProperties
 
 	// Arch specific versions of structs in GetProperties() prior to
 	// initialization in InitAndroidArchModule, lets call it `generalProperties`.
@@ -1207,29 +1217,7 @@
 				continue
 			}
 		}
-
-		// if the tagged dist file cannot be obtained from OutputFilesProvider,
-		// fall back to use OutputFileProducer
-		// TODO: remove this part after OutputFilesProvider fully replaces OutputFileProducer
-		if outputFileProducer, ok := m.module.(OutputFileProducer); ok {
-			// Call the OutputFiles(tag) method to get the paths associated with the tag.
-			distFilesForTag, err := outputFileProducer.OutputFiles(tag)
-			// If the tag was not supported and is not DefaultDistTag then it is an error.
-			// Failing to find paths for DefaultDistTag is not an error. It just means
-			// that the module type requires the legacy behavior.
-			if err != nil && tag != DefaultDistTag {
-				ctx.PropertyErrorf("dist.tag", "%s", err.Error())
-			}
-			distFiles = distFiles.addPathsForTag(tag, distFilesForTag...)
-		} else if tag != DefaultDistTag {
-			// If the tag was specified then it is an error if the module does not
-			// implement OutputFileProducer because there is no other way of accessing
-			// the paths for the specified tag.
-			ctx.PropertyErrorf("dist.tag",
-				"tag %s not supported because the module does not implement OutputFileProducer", tag)
-		}
 	}
-
 	return distFiles
 }
 
@@ -1321,7 +1309,11 @@
 	// hostEnabled is true if the host_supported property is true or the HostOrDeviceSupported
 	// value has the hostDefault bit set.
 	hostEnabled := proptools.BoolDefault(m.hostAndDeviceProperties.Host_supported, hod&hostDefault != 0)
-	return hod&hostCrossSupported != 0 && hostEnabled
+
+	// Default true for the Host_cross_supported property
+	hostCrossEnabled := proptools.BoolDefault(m.hostCrossProperties.Host_cross_supported, true)
+
+	return hod&hostCrossSupported != 0 && hostEnabled && hostCrossEnabled
 }
 
 func (m *ModuleBase) Platform() bool {
@@ -1779,6 +1771,8 @@
 		variables:         make(map[string]string),
 	}
 
+	setContainerInfo(ctx)
+
 	m.licenseMetadataFile = PathForModuleOut(ctx, "meta_lic")
 
 	dependencyInstallFiles, dependencyPackagingSpecs := m.computeInstallDeps(ctx)
@@ -2383,7 +2377,7 @@
 	// The name of the module.
 	moduleName string
 
-	// The tag that will be passed to the module's OutputFileProducer.OutputFiles(tag) method.
+	// The tag that will be used to get the specific output file(s).
 	tag string
 }
 
@@ -2437,14 +2431,7 @@
 	Srcs() Paths
 }
 
-// A module that implements OutputFileProducer can be referenced from any property that is tagged with `android:"path"`
-// using the ":module" syntax or ":module{.tag}" syntax and provides a list of output files to be used as if they were
-// listed in the property.
-type OutputFileProducer interface {
-	OutputFiles(tag string) (Paths, error)
-}
-
-// OutputFilesForModule returns the paths from an OutputFileProducer with the given tag.  On error, including if the
+// OutputFilesForModule returns the output file paths with the given tag. On error, including if the
 // module produced zero paths, it reports errors to the ctx and returns nil.
 func OutputFilesForModule(ctx PathContext, module blueprint.Module, tag string) Paths {
 	paths, err := outputFilesForModule(ctx, module, tag)
@@ -2455,7 +2442,7 @@
 	return paths
 }
 
-// OutputFileForModule returns the path from an OutputFileProducer with the given tag.  On error, including if the
+// OutputFileForModule returns the output file paths with the given tag.  On error, including if the
 // module produced zero or multiple paths, it reports errors to the ctx and returns nil.
 func OutputFileForModule(ctx PathContext, module blueprint.Module, tag string) Path {
 	paths, err := outputFilesForModule(ctx, module, tag)
@@ -2531,8 +2518,9 @@
 	} else if cta, isCta := ctx.(*singletonContextAdaptor); isCta {
 		providerData, _ := cta.moduleProvider(module, OutputFilesProvider)
 		outputFiles, _ = providerData.(OutputFilesInfo)
+	} else {
+		return nil, fmt.Errorf("unsupported context %q in method outputFilesForModuleFromProvider", reflect.TypeOf(ctx))
 	}
-	// TODO: Add a check for skipped context
 
 	if outputFiles.isEmpty() {
 		return nil, OutputFilesProviderNotSet
diff --git a/android/neverallow.go b/android/neverallow.go
index 62c5e59..ef4b8b8 100644
--- a/android/neverallow.go
+++ b/android/neverallow.go
@@ -237,6 +237,7 @@
 			Without("name", "init_first_stage").
 			Without("name", "init_first_stage.microdroid").
 			With("install_in_root", "true").
+			NotModuleType("prebuilt_root").
 			Because("install_in_root is only for init_first_stage."),
 	}
 }
diff --git a/android/packaging.go b/android/packaging.go
index ae412e1..c247ed2 100644
--- a/android/packaging.go
+++ b/android/packaging.go
@@ -17,6 +17,7 @@
 import (
 	"fmt"
 	"path/filepath"
+	"sort"
 	"strings"
 
 	"github.com/google/blueprint"
@@ -377,31 +378,59 @@
 // CopySpecsToDir is a helper that will add commands to the rule builder to copy the PackagingSpec
 // entries into the specified directory.
 func (p *PackagingBase) CopySpecsToDir(ctx ModuleContext, builder *RuleBuilder, specs map[string]PackagingSpec, dir WritablePath) (entries []string) {
-	if len(specs) == 0 {
+	dirsToSpecs := make(map[WritablePath]map[string]PackagingSpec)
+	dirsToSpecs[dir] = specs
+	return p.CopySpecsToDirs(ctx, builder, dirsToSpecs)
+}
+
+// CopySpecsToDirs is a helper that will add commands to the rule builder to copy the PackagingSpec
+// entries into corresponding directories.
+func (p *PackagingBase) CopySpecsToDirs(ctx ModuleContext, builder *RuleBuilder, dirsToSpecs map[WritablePath]map[string]PackagingSpec) (entries []string) {
+	empty := true
+	for _, specs := range dirsToSpecs {
+		if len(specs) > 0 {
+			empty = false
+			break
+		}
+	}
+	if empty {
 		return entries
 	}
+
 	seenDir := make(map[string]bool)
 	preparerPath := PathForModuleOut(ctx, "preparer.sh")
 	cmd := builder.Command().Tool(preparerPath)
 	var sb strings.Builder
 	sb.WriteString("set -e\n")
-	for _, k := range SortedKeys(specs) {
-		ps := specs[k]
-		destPath := filepath.Join(dir.String(), ps.relPathInPackage)
-		destDir := filepath.Dir(destPath)
-		entries = append(entries, ps.relPathInPackage)
-		if _, ok := seenDir[destDir]; !ok {
-			seenDir[destDir] = true
-			sb.WriteString(fmt.Sprintf("mkdir -p %s\n", destDir))
-		}
-		if ps.symlinkTarget == "" {
-			cmd.Implicit(ps.srcPath)
-			sb.WriteString(fmt.Sprintf("cp %s %s\n", ps.srcPath, destPath))
-		} else {
-			sb.WriteString(fmt.Sprintf("ln -sf %s %s\n", ps.symlinkTarget, destPath))
-		}
-		if ps.executable {
-			sb.WriteString(fmt.Sprintf("chmod a+x %s\n", destPath))
+
+	dirs := make([]WritablePath, 0, len(dirsToSpecs))
+	for dir, _ := range dirsToSpecs {
+		dirs = append(dirs, dir)
+	}
+	sort.Slice(dirs, func(i, j int) bool {
+		return dirs[i].String() < dirs[j].String()
+	})
+
+	for _, dir := range dirs {
+		specs := dirsToSpecs[dir]
+		for _, k := range SortedKeys(specs) {
+			ps := specs[k]
+			destPath := filepath.Join(dir.String(), ps.relPathInPackage)
+			destDir := filepath.Dir(destPath)
+			entries = append(entries, ps.relPathInPackage)
+			if _, ok := seenDir[destDir]; !ok {
+				seenDir[destDir] = true
+				sb.WriteString(fmt.Sprintf("mkdir -p %s\n", destDir))
+			}
+			if ps.symlinkTarget == "" {
+				cmd.Implicit(ps.srcPath)
+				sb.WriteString(fmt.Sprintf("cp %s %s\n", ps.srcPath, destPath))
+			} else {
+				sb.WriteString(fmt.Sprintf("ln -sf %s %s\n", ps.symlinkTarget, destPath))
+			}
+			if ps.executable {
+				sb.WriteString(fmt.Sprintf("chmod a+x %s\n", destPath))
+			}
 		}
 	}
 
diff --git a/android/paths.go b/android/paths.go
index 03772eb..dda48dd 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -463,8 +463,8 @@
 //   - glob, relative to the local module directory, resolves as filepath(s), relative to the local
 //     source directory.
 //   - other modules using the ":name{.tag}" syntax. These modules must implement SourceFileProducer
-//     or OutputFileProducer. These resolve as a filepath to an output filepath or generated source
-//     filepath.
+//     or set the OutputFilesProvider. These resolve as a filepath to an output filepath or generated
+//     source filepath.
 //
 // Properties passed as the paths argument must have been annotated with struct tag
 // `android:"path"` so that dependencies on SourceFileProducer modules will have already been handled by the
@@ -491,8 +491,8 @@
 //   - glob, relative to the local module directory, resolves as filepath(s), relative to the local
 //     source directory. Not valid in excludes.
 //   - other modules using the ":name{.tag}" syntax. These modules must implement SourceFileProducer
-//     or OutputFileProducer. These resolve as a filepath to an output filepath or generated source
-//     filepath.
+//     or set the OutputFilesProvider. These resolve as a filepath to an output filepath or generated
+//     source filepath.
 //
 // excluding the items (similarly resolved
 // Properties passed as the paths argument must have been annotated with struct tag
@@ -620,8 +620,8 @@
 //   - glob, relative to the local module directory, resolves as filepath(s), relative to the local
 //     source directory. Not valid in excludes.
 //   - other modules using the ":name{.tag}" syntax. These modules must implement SourceFileProducer
-//     or OutputFileProducer. These resolve as a filepath to an output filepath or generated source
-//     filepath.
+//     or set the OutputFilesProvider. These resolve as a filepath to an output filepath or generated
+//     source filepath.
 //
 // and a list of the module names of missing module dependencies are returned as the second return.
 // Properties passed as the paths argument must have been annotated with struct tag
diff --git a/android/rule_builder.go b/android/rule_builder.go
index 85e29bd..8b03124 100644
--- a/android/rule_builder.go
+++ b/android/rule_builder.go
@@ -58,6 +58,7 @@
 	sboxInputs       bool
 	sboxManifestPath WritablePath
 	missingDeps      []string
+	args             map[string]string
 }
 
 // NewRuleBuilder returns a newly created RuleBuilder.
@@ -78,6 +79,17 @@
 	return rb
 }
 
+// Set the phony_output argument.
+// This causes the output files to be ignored.
+// If the output isn't created, it's not treated as an error.
+// The build rule is run every time whether or not the output is created.
+func (rb *RuleBuilder) SetPhonyOutput() {
+	if rb.args == nil {
+		rb.args = make(map[string]string)
+	}
+	rb.args["phony_output"] = "true"
+}
+
 // RuleBuilderInstall is a tuple of install from and to locations.
 type RuleBuilderInstall struct {
 	From Path
@@ -726,6 +738,12 @@
 		commandString = proptools.NinjaEscape(commandString)
 	}
 
+	args_vars := make([]string, len(r.args))
+	i := 0
+	for k, _ := range r.args {
+		args_vars[i] = k
+		i++
+	}
 	r.ctx.Build(r.pctx, BuildParams{
 		Rule: r.ctx.Rule(r.pctx, name, blueprint.RuleParams{
 			Command:        commandString,
@@ -734,7 +752,7 @@
 			Rspfile:        proptools.NinjaEscape(rspFile),
 			RspfileContent: rspFileContent,
 			Pool:           pool,
-		}),
+		}, args_vars...),
 		Inputs:          rspFileInputs,
 		Implicits:       inputs,
 		OrderOnly:       r.OrderOnlys(),
@@ -744,6 +762,7 @@
 		Depfile:         depFile,
 		Deps:            depFormat,
 		Description:     desc,
+		Args:            r.args,
 	})
 }
 
diff --git a/android/testing.go b/android/testing.go
index 18fd3b3..e39a1a7 100644
--- a/android/testing.go
+++ b/android/testing.go
@@ -1018,31 +1018,21 @@
 	return normalizeStringMapRelativeToTop(m.config, m.module.VariablesForTests())
 }
 
-// OutputFiles first checks if module base outputFiles property has any output
+// OutputFiles checks if module base outputFiles property has any output
 // files can be used to return.
-// If not, it calls OutputFileProducer.OutputFiles on the
-// encapsulated module, exits the test immediately if there is an error and
+// Exits the test immediately if there is an error and
 // otherwise returns the result of calling Paths.RelativeToTop
 // on the returned Paths.
 func (m TestingModule) OutputFiles(t *testing.T, tag string) Paths {
-	// TODO: remove OutputFileProducer part
 	outputFiles := m.Module().base().outputFiles
 	if tag == "" && outputFiles.DefaultOutputFiles != nil {
 		return outputFiles.DefaultOutputFiles.RelativeToTop()
 	} else if taggedOutputFiles, hasTag := outputFiles.TaggedOutputFiles[tag]; hasTag {
-		return taggedOutputFiles
+		return taggedOutputFiles.RelativeToTop()
 	}
 
-	producer, ok := m.module.(OutputFileProducer)
-	if !ok {
-		t.Fatalf("%q must implement OutputFileProducer\n", m.module.Name())
-	}
-	paths, err := producer.OutputFiles(tag)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	return paths.RelativeToTop()
+	t.Fatal(fmt.Errorf("No test output file has been set for tag %q", tag))
+	return nil
 }
 
 // TestingSingleton is wrapper around an android.Singleton that provides methods to find information about individual
diff --git a/android/util.go b/android/util.go
index e21e66b..3c0af2f 100644
--- a/android/util.go
+++ b/android/util.go
@@ -201,6 +201,12 @@
 	return listsDiffer, diff1, diff2
 }
 
+// Returns true if the two lists have common elements.
+func HasIntersection[T comparable](l1, l2 []T) bool {
+	_, a, b := ListSetDifference(l1, l2)
+	return len(a)+len(b) < len(setFromList(l1))+len(setFromList(l2))
+}
+
 // Returns true if the given string s is prefixed with any string in the given prefix list.
 func HasAnyPrefix(s string, prefixList []string) bool {
 	for _, prefix := range prefixList {
diff --git a/android/util_test.go b/android/util_test.go
index 8e73d83..6537d69 100644
--- a/android/util_test.go
+++ b/android/util_test.go
@@ -818,3 +818,52 @@
 		})
 	}
 }
+
+var hasIntersectionTestCases = []struct {
+	name     string
+	l1       []string
+	l2       []string
+	expected bool
+}{
+	{
+		name:     "empty",
+		l1:       []string{"a", "b", "c"},
+		l2:       []string{},
+		expected: false,
+	},
+	{
+		name:     "both empty",
+		l1:       []string{},
+		l2:       []string{},
+		expected: false,
+	},
+	{
+		name:     "identical",
+		l1:       []string{"a", "b", "c"},
+		l2:       []string{"a", "b", "c"},
+		expected: true,
+	},
+	{
+		name:     "duplicates",
+		l1:       []string{"a", "a", "a"},
+		l2:       []string{"a", "b", "c"},
+		expected: true,
+	},
+	{
+		name:     "duplicates with no intersection",
+		l1:       []string{"d", "d", "d", "d"},
+		l2:       []string{"a", "b", "c"},
+		expected: false,
+	},
+}
+
+func TestHasIntersection(t *testing.T) {
+	for _, testCase := range hasIntersectionTestCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			hasIntersection := HasIntersection(testCase.l1, testCase.l2)
+			if !reflect.DeepEqual(hasIntersection, testCase.expected) {
+				t.Errorf("expected %#v, got %#v", testCase.expected, hasIntersection)
+			}
+		})
+	}
+}
diff --git a/android/variable.go b/android/variable.go
index d144f7d..3b02bc7 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -132,9 +132,11 @@
 				Keep_symbols                 *bool
 				Keep_symbols_and_debug_frame *bool
 			}
-			Static_libs       []string
-			Whole_static_libs []string
-			Shared_libs       []string
+			Static_libs         []string
+			Exclude_static_libs []string
+			Whole_static_libs   []string
+			Shared_libs         []string
+			Jni_libs            []string
 
 			Cmdline []string
 
diff --git a/androidmk/parser/parser_test.go b/androidmk/parser/parser_test.go
index db3313d..fb03c23 100644
--- a/androidmk/parser/parser_test.go
+++ b/androidmk/parser/parser_test.go
@@ -86,20 +86,19 @@
 	},
 	{
 		name: "Blank line in rule's command",
-		in:   `all:
+		in: `all:
 	echo first line
 
 	echo second line`,
 		out: []Node{
 			&Rule{
-				Target: SimpleMakeString("all", NoPos),
-				RecipePos: NoPos,
-				Recipe: "echo first line\necho second line",
+				Target:        SimpleMakeString("all", NoPos),
+				RecipePos:     NoPos,
+				Recipe:        "echo first line\necho second line",
 				Prerequisites: SimpleMakeString("", NoPos),
 			},
 		},
 	},
-
 }
 
 func TestParse(t *testing.T) {
diff --git a/apex/Android.bp b/apex/Android.bp
index abae9e2..17fdfc3 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -37,6 +37,7 @@
         "apex_test.go",
         "bootclasspath_fragment_test.go",
         "classpath_element_test.go",
+        "container_test.go",
         "dexpreopt_bootjars_test.go",
         "platform_bootclasspath_test.go",
         "systemserver_classpath_fragment_test.go",
diff --git a/apex/apex.go b/apex/apex.go
index 10fe372..5a75d3e 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -703,7 +703,6 @@
 	rustLibVariations := append(
 		target.Variations(), []blueprint.Variation{
 			{Mutator: "rust_libraries", Variation: "dylib"},
-			{Mutator: "link", Variation: ""},
 		}...,
 	)
 
@@ -2663,12 +2662,20 @@
 	})
 }
 
+// TODO (b/221087384): Remove this allowlist
+var (
+	updatableApexesWithCurrentMinSdkVersionAllowlist = []string{"com.android.profiling"}
+)
+
 // checkUpdatable enforces APEX and its transitive dep properties to have desired values for updatable APEXes.
 func (a *apexBundle) checkUpdatable(ctx android.ModuleContext) {
 	if a.Updatable() {
 		if a.minSdkVersionValue(ctx) == "" {
 			ctx.PropertyErrorf("updatable", "updatable APEXes should set min_sdk_version as well")
 		}
+		if a.minSdkVersion(ctx).IsCurrent() && !android.InList(ctx.ModuleName(), updatableApexesWithCurrentMinSdkVersionAllowlist) {
+			ctx.PropertyErrorf("updatable", "updatable APEXes should not set min_sdk_version to current. Please use a finalized API level or a recognized in-development codename")
+		}
 		if a.UsePlatformApis() {
 			ctx.PropertyErrorf("updatable", "updatable APEXes can't use platform APIs")
 		}
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 15c713b..a2dbbfc 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -11721,3 +11721,20 @@
 
 	java.CheckModuleHasDependency(t, res.TestContext, "myoverrideapex", "android_common_myoverrideapex_myoverrideapex", "foo")
 }
+
+func TestUpdatableApexMinSdkVersionCurrent(t *testing.T) {
+	testApexError(t, `"myapex" .*: updatable: updatable APEXes should not set min_sdk_version to current. Please use a finalized API level or a recognized in-development codename`, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			updatable: true,
+			min_sdk_version: "current",
+		}
+
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+	`)
+}
diff --git a/apex/container_test.go b/apex/container_test.go
new file mode 100644
index 0000000..3931174
--- /dev/null
+++ b/apex/container_test.go
@@ -0,0 +1,329 @@
+// Copyright 2024 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package apex
+
+import (
+	"android/soong/android"
+	"android/soong/java"
+	"fmt"
+	"testing"
+)
+
+var checkContainerMatch = func(t *testing.T, name string, container string, expected bool, actual bool) {
+	errorMessage := fmt.Sprintf("module %s container %s value differ", name, container)
+	android.AssertBoolEquals(t, errorMessage, expected, actual)
+}
+
+func TestApexDepsContainers(t *testing.T) {
+	result := android.GroupFixturePreparers(
+		prepareForApexTest,
+		java.PrepareForTestWithJavaSdkLibraryFiles,
+		java.FixtureWithLastReleaseApis("mybootclasspathlib"),
+	).RunTestWithBp(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			bootclasspath_fragments: [
+				"mybootclasspathfragment",
+			],
+			updatable: true,
+			min_sdk_version: "30",
+		}
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+		bootclasspath_fragment {
+			name: "mybootclasspathfragment",
+			contents: [
+				"mybootclasspathlib",
+			],
+			apex_available: [
+				"myapex",
+			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
+		}
+		java_sdk_library {
+			name: "mybootclasspathlib",
+			srcs: [
+				"mybootclasspathlib.java",
+			],
+			apex_available: [
+				"myapex",
+			],
+			compile_dex: true,
+			static_libs: [
+				"foo",
+				"baz",
+			],
+			libs: [
+				"bar",
+			],
+			min_sdk_version: "30",
+		}
+		java_library {
+			name: "foo",
+			srcs:[
+				"A.java",
+			],
+			apex_available: [
+				"myapex",
+			],
+			min_sdk_version: "30",
+		}
+		java_library {
+			name: "bar",
+			srcs:[
+				"A.java",
+			],
+			min_sdk_version: "30",
+		}
+		java_library {
+			name: "baz",
+			srcs:[
+				"A.java",
+			],
+			apex_available: [
+				"//apex_available:platform",
+				"myapex",
+			],
+			min_sdk_version: "30",
+		}
+	`)
+	testcases := []struct {
+		moduleName        string
+		variant           string
+		isSystemContainer bool
+		isApexContainer   bool
+	}{
+		{
+			moduleName:        "mybootclasspathlib",
+			variant:           "android_common_myapex",
+			isSystemContainer: true,
+			isApexContainer:   true,
+		},
+		{
+			moduleName:        "mybootclasspathlib.impl",
+			variant:           "android_common_apex30",
+			isSystemContainer: true,
+			isApexContainer:   true,
+		},
+		{
+			moduleName:        "mybootclasspathlib.stubs",
+			variant:           "android_common",
+			isSystemContainer: true,
+			isApexContainer:   false,
+		},
+		{
+			moduleName:        "foo",
+			variant:           "android_common_apex30",
+			isSystemContainer: true,
+			isApexContainer:   true,
+		},
+		{
+			moduleName:        "bar",
+			variant:           "android_common",
+			isSystemContainer: true,
+			isApexContainer:   false,
+		},
+		{
+			moduleName:        "baz",
+			variant:           "android_common_apex30",
+			isSystemContainer: true,
+			isApexContainer:   true,
+		},
+	}
+
+	for _, c := range testcases {
+		m := result.ModuleForTests(c.moduleName, c.variant)
+		containers, _ := android.OtherModuleProvider(result.TestContext.OtherModuleProviderAdaptor(), m.Module(), android.ContainersInfoProvider)
+		belongingContainers := containers.BelongingContainers()
+		checkContainerMatch(t, c.moduleName, "system", c.isSystemContainer, android.InList(android.SystemContainer, belongingContainers))
+		checkContainerMatch(t, c.moduleName, "apex", c.isApexContainer, android.InList(android.ApexContainer, belongingContainers))
+	}
+}
+
+func TestNonUpdatableApexDepsContainers(t *testing.T) {
+	result := android.GroupFixturePreparers(
+		prepareForApexTest,
+		java.PrepareForTestWithJavaSdkLibraryFiles,
+		java.FixtureWithLastReleaseApis("mybootclasspathlib"),
+	).RunTestWithBp(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			bootclasspath_fragments: [
+				"mybootclasspathfragment",
+			],
+			updatable: false,
+		}
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+		bootclasspath_fragment {
+			name: "mybootclasspathfragment",
+			contents: [
+				"mybootclasspathlib",
+			],
+			apex_available: [
+				"myapex",
+			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
+		}
+		java_sdk_library {
+			name: "mybootclasspathlib",
+			srcs: [
+				"mybootclasspathlib.java",
+			],
+			apex_available: [
+				"myapex",
+			],
+			compile_dex: true,
+			static_libs: [
+				"foo",
+			],
+			libs: [
+				"bar",
+			],
+		}
+		java_library {
+			name: "foo",
+			srcs:[
+				"A.java",
+			],
+			apex_available: [
+				"myapex",
+			],
+		}
+		java_library {
+			name: "bar",
+			srcs:[
+				"A.java",
+			],
+		}
+	`)
+	testcases := []struct {
+		moduleName        string
+		variant           string
+		isSystemContainer bool
+		isApexContainer   bool
+	}{
+		{
+			moduleName:        "mybootclasspathlib",
+			variant:           "android_common_myapex",
+			isSystemContainer: true,
+			isApexContainer:   true,
+		},
+		{
+			moduleName:        "mybootclasspathlib.impl",
+			variant:           "android_common_apex10000",
+			isSystemContainer: true,
+			isApexContainer:   true,
+		},
+		{
+			moduleName:        "mybootclasspathlib.stubs",
+			variant:           "android_common",
+			isSystemContainer: true,
+			isApexContainer:   false,
+		},
+		{
+			moduleName:        "foo",
+			variant:           "android_common_apex10000",
+			isSystemContainer: true,
+			isApexContainer:   true,
+		},
+		{
+			moduleName:        "bar",
+			variant:           "android_common",
+			isSystemContainer: true,
+			isApexContainer:   false,
+		},
+	}
+
+	for _, c := range testcases {
+		m := result.ModuleForTests(c.moduleName, c.variant)
+		containers, _ := android.OtherModuleProvider(result.TestContext.OtherModuleProviderAdaptor(), m.Module(), android.ContainersInfoProvider)
+		belongingContainers := containers.BelongingContainers()
+		checkContainerMatch(t, c.moduleName, "system", c.isSystemContainer, android.InList(android.SystemContainer, belongingContainers))
+		checkContainerMatch(t, c.moduleName, "apex", c.isApexContainer, android.InList(android.ApexContainer, belongingContainers))
+	}
+}
+
+func TestUpdatableAndNonUpdatableApexesIdenticalMinSdkVersion(t *testing.T) {
+	result := android.GroupFixturePreparers(
+		prepareForApexTest,
+		java.PrepareForTestWithJavaSdkLibraryFiles,
+		android.FixtureMergeMockFs(android.MockFS{
+			"system/sepolicy/apex/myapex_non_updatable-file_contexts": nil,
+			"system/sepolicy/apex/myapex_updatable-file_contexts":     nil,
+		}),
+	).RunTestWithBp(t, `
+		apex {
+			name: "myapex_non_updatable",
+			key: "myapex_non_updatable.key",
+			java_libs: [
+				"foo",
+			],
+			updatable: false,
+			min_sdk_version: "30",
+		}
+		apex_key {
+			name: "myapex_non_updatable.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+
+		apex {
+			name: "myapex_updatable",
+			key: "myapex_updatable.key",
+			java_libs: [
+				"foo",
+			],
+			updatable: true,
+			min_sdk_version: "30",
+		}
+		apex_key {
+			name: "myapex_updatable.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+
+		java_library {
+			name: "foo",
+			srcs:[
+				"A.java",
+			],
+			apex_available: [
+				"myapex_non_updatable",
+				"myapex_updatable",
+			],
+			min_sdk_version: "30",
+			sdk_version: "current",
+		}
+	`)
+
+	fooApexVariant := result.ModuleForTests("foo", "android_common_apex30")
+	containers, _ := android.OtherModuleProvider(result.TestContext.OtherModuleProviderAdaptor(), fooApexVariant.Module(), android.ContainersInfoProvider)
+	belongingContainers := containers.BelongingContainers()
+	checkContainerMatch(t, "foo", "system", true, android.InList(android.SystemContainer, belongingContainers))
+	checkContainerMatch(t, "foo", "apex", true, android.InList(android.ApexContainer, belongingContainers))
+}
diff --git a/cc/cc.go b/cc/cc.go
index 740be3a..64b2465 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -48,10 +48,10 @@
 	ctx.RegisterModuleType("cc_defaults", defaultsFactory)
 
 	ctx.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.BottomUp("sdk", sdkMutator).Parallel()
+		ctx.Transition("sdk", &sdkTransitionMutator{})
 		ctx.BottomUp("llndk", llndkMutator).Parallel()
-		ctx.BottomUp("link", LinkageMutator).Parallel()
-		ctx.BottomUp("version", versionMutator).Parallel()
+		ctx.Transition("link", &linkageTransitionMutator{})
+		ctx.Transition("version", &versionTransitionMutator{})
 		ctx.BottomUp("begin", BeginMutator).Parallel()
 	})
 
@@ -1867,8 +1867,10 @@
 		"libdl":         true,
 		"libz":          true,
 		// art apex
+		// TODO(b/234351700): Remove this when com.android.art.debug is gone.
 		"libandroidio":    true,
 		"libdexfile":      true,
+		"libdexfiled":     true, // com.android.art.debug only
 		"libnativebridge": true,
 		"libnativehelper": true,
 		"libnativeloader": true,
diff --git a/cc/ccdeps.go b/cc/ccdeps.go
index d30abba..469fe31 100644
--- a/cc/ccdeps.go
+++ b/cc/ccdeps.go
@@ -85,9 +85,8 @@
 	moduleDeps := ccDeps{}
 	moduleInfos := map[string]ccIdeInfo{}
 
-	// Track which projects have already had CMakeLists.txt generated to keep the first
-	// variant for each project.
-	seenProjects := map[string]bool{}
+	// Track if best variant (device arch match) has been found.
+	bestVariantFound := map[string]bool{}
 
 	pathToCC, _ := evalVariable(ctx, "${config.ClangBin}/")
 	moduleDeps.C_clang = fmt.Sprintf("%s%s", buildCMakePath(pathToCC), cClang)
@@ -96,7 +95,7 @@
 	ctx.VisitAllModules(func(module android.Module) {
 		if ccModule, ok := module.(*Module); ok {
 			if compiledModule, ok := ccModule.compiler.(CompiledInterface); ok {
-				generateCLionProjectData(ctx, compiledModule, ccModule, seenProjects, moduleInfos)
+				generateCLionProjectData(ctx, compiledModule, ccModule, bestVariantFound, moduleInfos)
 			}
 		}
 	})
@@ -180,26 +179,30 @@
 }
 
 func generateCLionProjectData(ctx android.SingletonContext, compiledModule CompiledInterface,
-	ccModule *Module, seenProjects map[string]bool, moduleInfos map[string]ccIdeInfo) {
+	ccModule *Module, bestVariantFound map[string]bool, moduleInfos map[string]ccIdeInfo) {
+	moduleName := ccModule.ModuleBase.Name()
 	srcs := compiledModule.Srcs()
+
+	// Skip if best variant has already been found.
+	if bestVariantFound[moduleName] {
+		return
+	}
+
+	// Skip if sources are empty.
 	if len(srcs) == 0 {
 		return
 	}
 
-	// Only keep the DeviceArch variant module.
-	if ctx.DeviceConfig().DeviceArch() != ccModule.ModuleBase.Arch().ArchType.Name {
+	// Check if device arch matches, in which case this is the best variant and takes precedence.
+	if ccModule.Device() && ccModule.ModuleBase.Arch().ArchType.Name == ctx.DeviceConfig().DeviceArch() {
+		bestVariantFound[moduleName] = true
+	} else if _, ok := moduleInfos[moduleName]; ok {
+		// Skip because this isn't the best variant and a previous one has already been added.
+		// Heuristically, ones that appear first are likely to be more relevant.
 		return
 	}
 
-	clionProjectLocation := getCMakeListsForModule(ccModule, ctx)
-	if seenProjects[clionProjectLocation] {
-		return
-	}
-
-	seenProjects[clionProjectLocation] = true
-
-	name := ccModule.ModuleBase.Name()
-	dpInfo := moduleInfos[name]
+	dpInfo := ccIdeInfo{}
 
 	dpInfo.Path = append(dpInfo.Path, path.Dir(ctx.BlueprintFile(ccModule)))
 	dpInfo.Srcs = append(dpInfo.Srcs, srcs.Strings()...)
@@ -216,9 +219,9 @@
 	dpInfo.Local_Cpp_flags = parseCompilerCCParameters(ctx, ccModule.flags.Local.CppFlags)
 	dpInfo.System_include_flags = parseCompilerCCParameters(ctx, ccModule.flags.SystemIncludeFlags)
 
-	dpInfo.Module_name = name
+	dpInfo.Module_name = moduleName
 
-	moduleInfos[name] = dpInfo
+	moduleInfos[moduleName] = dpInfo
 }
 
 type Deal struct {
diff --git a/cc/config/global.go b/cc/config/global.go
index 62a4765..bf2502f 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -397,8 +397,8 @@
 
 	// prebuilts/clang default settings.
 	ClangDefaultBase         = "prebuilts/clang/host"
-	ClangDefaultVersion      = "clang-r522817"
-	ClangDefaultShortVersion = "18"
+	ClangDefaultVersion      = "clang-r530567"
+	ClangDefaultShortVersion = "19"
 
 	// Directories with warnings from Android.bp files.
 	WarningAllowedProjects = []string{
diff --git a/cc/library.go b/cc/library.go
index 560b1ae..6dd5b56 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -19,6 +19,7 @@
 	"io"
 	"path/filepath"
 	"regexp"
+	"slices"
 	"strconv"
 	"strings"
 	"sync"
@@ -711,7 +712,7 @@
 	setStubsVersion(string)
 	stubsVersion() string
 
-	stubsVersions(ctx android.BaseMutatorContext) []string
+	stubsVersions(ctx android.BaseModuleContext) []string
 	setAllStubsVersions([]string)
 	allStubsVersions() []string
 
@@ -1903,7 +1904,7 @@
 	return BoolDefault(library.Properties.Stubs.Implementation_installable, true)
 }
 
-func (library *libraryDecorator) stubsVersions(ctx android.BaseMutatorContext) []string {
+func (library *libraryDecorator) stubsVersions(ctx android.BaseModuleContext) []string {
 	if !library.hasStubsVariants() {
 		return nil
 	}
@@ -2064,26 +2065,26 @@
 
 // connects a shared library to a static library in order to reuse its .o files to avoid
 // compiling source files twice.
-func reuseStaticLibrary(mctx android.BottomUpMutatorContext, static, shared *Module) {
-	if staticCompiler, ok := static.compiler.(*libraryDecorator); ok {
-		sharedCompiler := shared.compiler.(*libraryDecorator)
+func reuseStaticLibrary(ctx android.BottomUpMutatorContext, shared *Module) {
+	if sharedCompiler, ok := shared.compiler.(*libraryDecorator); ok {
 
 		// Check libraries in addition to cflags, since libraries may be exporting different
 		// include directories.
-		if len(staticCompiler.StaticProperties.Static.Cflags.GetOrDefault(mctx, nil)) == 0 &&
-			len(sharedCompiler.SharedProperties.Shared.Cflags.GetOrDefault(mctx, nil)) == 0 &&
-			len(staticCompiler.StaticProperties.Static.Whole_static_libs) == 0 &&
+		if len(sharedCompiler.StaticProperties.Static.Cflags.GetOrDefault(ctx, nil)) == 0 &&
+			len(sharedCompiler.SharedProperties.Shared.Cflags.GetOrDefault(ctx, nil)) == 0 &&
+			len(sharedCompiler.StaticProperties.Static.Whole_static_libs) == 0 &&
 			len(sharedCompiler.SharedProperties.Shared.Whole_static_libs) == 0 &&
-			len(staticCompiler.StaticProperties.Static.Static_libs) == 0 &&
+			len(sharedCompiler.StaticProperties.Static.Static_libs) == 0 &&
 			len(sharedCompiler.SharedProperties.Shared.Static_libs) == 0 &&
-			len(staticCompiler.StaticProperties.Static.Shared_libs) == 0 &&
+			len(sharedCompiler.StaticProperties.Static.Shared_libs) == 0 &&
 			len(sharedCompiler.SharedProperties.Shared.Shared_libs) == 0 &&
 			// Compare System_shared_libs properties with nil because empty lists are
 			// semantically significant for them.
-			staticCompiler.StaticProperties.Static.System_shared_libs == nil &&
+			sharedCompiler.StaticProperties.Static.System_shared_libs == nil &&
 			sharedCompiler.SharedProperties.Shared.System_shared_libs == nil {
 
-			mctx.AddInterVariantDependency(reuseObjTag, shared, static)
+			// TODO: namespaces?
+			ctx.AddVariationDependencies([]blueprint.Variation{{"link", "static"}}, reuseObjTag, ctx.ModuleName())
 			sharedCompiler.baseCompiler.Properties.OriginalSrcs =
 				sharedCompiler.baseCompiler.Properties.Srcs
 			sharedCompiler.baseCompiler.Properties.Srcs = nil
@@ -2091,19 +2092,21 @@
 		}
 
 		// This dep is just to reference static variant from shared variant
-		mctx.AddInterVariantDependency(staticVariantTag, shared, static)
+		ctx.AddVariationDependencies([]blueprint.Variation{{"link", "static"}}, staticVariantTag, ctx.ModuleName())
 	}
 }
 
-// LinkageMutator adds "static" or "shared" variants for modules depending
+// linkageTransitionMutator adds "static" or "shared" variants for modules depending
 // on whether the module can be built as a static library or a shared library.
-func LinkageMutator(mctx android.BottomUpMutatorContext) {
+type linkageTransitionMutator struct{}
+
+func (linkageTransitionMutator) Split(ctx android.BaseModuleContext) []string {
 	ccPrebuilt := false
-	if m, ok := mctx.Module().(*Module); ok && m.linker != nil {
+	if m, ok := ctx.Module().(*Module); ok && m.linker != nil {
 		_, ccPrebuilt = m.linker.(prebuiltLibraryInterface)
 	}
 	if ccPrebuilt {
-		library := mctx.Module().(*Module).linker.(prebuiltLibraryInterface)
+		library := ctx.Module().(*Module).linker.(prebuiltLibraryInterface)
 
 		// Differentiate between header only and building an actual static/shared library
 		buildStatic := library.buildStatic()
@@ -2112,75 +2115,118 @@
 			// Always create both the static and shared variants for prebuilt libraries, and then disable the one
 			// that is not being used.  This allows them to share the name of a cc_library module, which requires that
 			// all the variants of the cc_library also exist on the prebuilt.
-			modules := mctx.CreateLocalVariations("static", "shared")
-			static := modules[0].(*Module)
-			shared := modules[1].(*Module)
-
-			static.linker.(prebuiltLibraryInterface).setStatic()
-			shared.linker.(prebuiltLibraryInterface).setShared()
-
-			if buildShared {
-				mctx.AliasVariation("shared")
-			} else if buildStatic {
-				mctx.AliasVariation("static")
-			}
-
-			if !buildStatic {
-				static.linker.(prebuiltLibraryInterface).disablePrebuilt()
-			}
-			if !buildShared {
-				shared.linker.(prebuiltLibraryInterface).disablePrebuilt()
-			}
+			return []string{"static", "shared"}
 		} else {
 			// Header only
 		}
-
-	} else if library, ok := mctx.Module().(LinkableInterface); ok && (library.CcLibraryInterface() || library.RustLibraryInterface()) {
+	} else if library, ok := ctx.Module().(LinkableInterface); ok && (library.CcLibraryInterface() || library.RustLibraryInterface()) {
 		// Non-cc.Modules may need an empty variant for their mutators.
 		variations := []string{}
 		if library.NonCcVariants() {
 			variations = append(variations, "")
 		}
 		isLLNDK := false
-		if m, ok := mctx.Module().(*Module); ok {
+		if m, ok := ctx.Module().(*Module); ok {
 			isLLNDK = m.IsLlndk()
 		}
 		buildStatic := library.BuildStaticVariant() && !isLLNDK
 		buildShared := library.BuildSharedVariant()
 		if buildStatic && buildShared {
-			variations := append([]string{"static", "shared"}, variations...)
-
-			modules := mctx.CreateLocalVariations(variations...)
-			static := modules[0].(LinkableInterface)
-			shared := modules[1].(LinkableInterface)
-			static.SetStatic()
-			shared.SetShared()
-
-			if _, ok := library.(*Module); ok {
-				reuseStaticLibrary(mctx, static.(*Module), shared.(*Module))
-			}
-			mctx.AliasVariation("shared")
+			variations = append([]string{"static", "shared"}, variations...)
+			return variations
 		} else if buildStatic {
-			variations := append([]string{"static"}, variations...)
-
-			modules := mctx.CreateLocalVariations(variations...)
-			modules[0].(LinkableInterface).SetStatic()
-			mctx.AliasVariation("static")
+			variations = append([]string{"static"}, variations...)
 		} else if buildShared {
-			variations := append([]string{"shared"}, variations...)
-
-			modules := mctx.CreateLocalVariations(variations...)
-			modules[0].(LinkableInterface).SetShared()
-			mctx.AliasVariation("shared")
-		} else if len(variations) > 0 {
-			mctx.CreateLocalVariations(variations...)
-			mctx.AliasVariation(variations[0])
+			variations = append([]string{"shared"}, variations...)
 		}
-		if library.BuildRlibVariant() && library.IsRustFFI() && !buildStatic {
+
+		if len(variations) > 0 {
+			return variations
+		}
+	}
+	return []string{""}
+}
+
+func (linkageTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
+	return ""
+}
+
+func (linkageTransitionMutator) IncomingTransition(ctx android.IncomingTransitionContext, incomingVariation string) string {
+	ccPrebuilt := false
+	if m, ok := ctx.Module().(*Module); ok && m.linker != nil {
+		_, ccPrebuilt = m.linker.(prebuiltLibraryInterface)
+	}
+	if ccPrebuilt {
+		if incomingVariation != "" {
+			return incomingVariation
+		}
+		library := ctx.Module().(*Module).linker.(prebuiltLibraryInterface)
+		if library.buildShared() {
+			return "shared"
+		} else if library.buildStatic() {
+			return "static"
+		}
+		return ""
+	} else if library, ok := ctx.Module().(LinkableInterface); ok && library.CcLibraryInterface() {
+		isLLNDK := false
+		if m, ok := ctx.Module().(*Module); ok {
+			isLLNDK = m.IsLlndk()
+		}
+		buildStatic := library.BuildStaticVariant() && !isLLNDK
+		buildShared := library.BuildSharedVariant()
+		if library.BuildRlibVariant() && library.IsRustFFI() && !buildStatic && (incomingVariation == "static" || incomingVariation == "") {
 			// Rust modules do not build static libs, but rlibs are used as if they
 			// were via `static_libs`. Thus we need to alias the BuildRlibVariant
 			// to "static" for Rust FFI libraries.
-			mctx.CreateAliasVariation("static", "")
+			return ""
+		}
+		if incomingVariation != "" {
+			return incomingVariation
+		}
+		if buildShared {
+			return "shared"
+		} else if buildStatic {
+			return "static"
+		}
+		return ""
+	}
+	return ""
+}
+
+func (linkageTransitionMutator) Mutate(ctx android.BottomUpMutatorContext, variation string) {
+	ccPrebuilt := false
+	if m, ok := ctx.Module().(*Module); ok && m.linker != nil {
+		_, ccPrebuilt = m.linker.(prebuiltLibraryInterface)
+	}
+	if ccPrebuilt {
+		library := ctx.Module().(*Module).linker.(prebuiltLibraryInterface)
+		if variation == "static" {
+			library.setStatic()
+			if !library.buildStatic() {
+				library.disablePrebuilt()
+			}
+		} else if variation == "shared" {
+			library.setShared()
+			if !library.buildShared() {
+				library.disablePrebuilt()
+			}
+		}
+	} else if library, ok := ctx.Module().(LinkableInterface); ok && library.CcLibraryInterface() {
+		if variation == "static" {
+			library.SetStatic()
+		} else if variation == "shared" {
+			library.SetShared()
+			var isLLNDK bool
+			if m, ok := ctx.Module().(*Module); ok {
+				isLLNDK = m.IsLlndk()
+			}
+			buildStatic := library.BuildStaticVariant() && !isLLNDK
+			buildShared := library.BuildSharedVariant()
+			if buildStatic && buildShared {
+				if _, ok := library.(*Module); ok {
+					reuseStaticLibrary(ctx, library.(*Module))
+				}
+			}
 		}
 	}
 }
@@ -2204,64 +2250,14 @@
 	}
 }
 
-func createVersionVariations(mctx android.BottomUpMutatorContext, versions []string) {
-	// "" is for the non-stubs (implementation) variant for system modules, or the LLNDK variant
-	// for LLNDK modules.
-	variants := append(android.CopyOf(versions), "")
-
-	m := mctx.Module().(*Module)
-	isLLNDK := m.IsLlndk()
-	isVendorPublicLibrary := m.IsVendorPublicLibrary()
-	isImportedApiLibrary := m.isImportedApiLibrary()
-
-	modules := mctx.CreateLocalVariations(variants...)
-	for i, m := range modules {
-
-		if variants[i] != "" || isLLNDK || isVendorPublicLibrary || isImportedApiLibrary {
-			// A stubs or LLNDK stubs variant.
-			c := m.(*Module)
-			if c.sanitize != nil {
-				c.sanitize.Properties.ForceDisable = true
-			}
-			if c.stl != nil {
-				c.stl.Properties.Stl = StringPtr("none")
-			}
-			c.Properties.PreventInstall = true
-			lib := moduleLibraryInterface(m)
-			isLatest := i == (len(versions) - 1)
-			lib.setBuildStubs(isLatest)
-
-			if variants[i] != "" {
-				// A non-LLNDK stubs module is hidden from make and has a dependency from the
-				// implementation module to the stubs module.
-				c.Properties.HideFromMake = true
-				lib.setStubsVersion(variants[i])
-				mctx.AddInterVariantDependency(stubImplDepTag, modules[len(modules)-1], modules[i])
-			}
-		}
-	}
-	mctx.AliasVariation("")
-	latestVersion := ""
-	if len(versions) > 0 {
-		latestVersion = versions[len(versions)-1]
-	}
-	mctx.CreateAliasVariation("latest", latestVersion)
-}
-
-func createPerApiVersionVariations(mctx android.BottomUpMutatorContext, minSdkVersion string) {
+func perApiVersionVariations(mctx android.BaseModuleContext, minSdkVersion string) []string {
 	from, err := nativeApiLevelFromUser(mctx, minSdkVersion)
 	if err != nil {
 		mctx.PropertyErrorf("min_sdk_version", err.Error())
-		return
+		return []string{""}
 	}
 
-	versionStrs := ndkLibraryVersions(mctx, from)
-	modules := mctx.CreateLocalVariations(versionStrs...)
-
-	for i, module := range modules {
-		module.(*Module).Properties.Sdk_version = StringPtr(versionStrs[i])
-		module.(*Module).Properties.Min_sdk_version = StringPtr(versionStrs[i])
-	}
+	return ndkLibraryVersions(mctx, from)
 }
 
 func canBeOrLinkAgainstVersionVariants(module interface {
@@ -2291,7 +2287,7 @@
 }
 
 // setStubsVersions normalizes the versions in the Stubs.Versions property into MutatedProperties.AllStubsVersions.
-func setStubsVersions(mctx android.BottomUpMutatorContext, library libraryInterface, module *Module) {
+func setStubsVersions(mctx android.BaseModuleContext, library libraryInterface, module *Module) {
 	if !library.buildShared() || !canBeVersionVariant(module) {
 		return
 	}
@@ -2304,25 +2300,98 @@
 	library.setAllStubsVersions(versions)
 }
 
-// versionMutator splits a module into the mandatory non-stubs variant
+// versionTransitionMutator splits a module into the mandatory non-stubs variant
 // (which is unnamed) and zero or more stubs variants.
-func versionMutator(mctx android.BottomUpMutatorContext) {
-	if mctx.Os() != android.Android {
-		return
+type versionTransitionMutator struct{}
+
+func (versionTransitionMutator) Split(ctx android.BaseModuleContext) []string {
+	if ctx.Os() != android.Android {
+		return []string{""}
 	}
 
-	m, ok := mctx.Module().(*Module)
-	if library := moduleLibraryInterface(mctx.Module()); library != nil && canBeVersionVariant(m) {
-		setStubsVersions(mctx, library, m)
+	m, ok := ctx.Module().(*Module)
+	if library := moduleLibraryInterface(ctx.Module()); library != nil && canBeVersionVariant(m) {
+		setStubsVersions(ctx, library, m)
 
-		createVersionVariations(mctx, library.allStubsVersions())
-		return
+		return append(slices.Clone(library.allStubsVersions()), "")
+	} else if ok && m.SplitPerApiLevel() && m.IsSdkVariant() {
+		return perApiVersionVariations(ctx, m.MinSdkVersion())
 	}
 
-	if ok {
-		if m.SplitPerApiLevel() && m.IsSdkVariant() {
-			createPerApiVersionVariations(mctx, m.MinSdkVersion())
+	return []string{""}
+}
+
+func (versionTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
+	return ""
+}
+
+func (versionTransitionMutator) IncomingTransition(ctx android.IncomingTransitionContext, incomingVariation string) string {
+	if ctx.Os() != android.Android {
+		return ""
+	}
+	m, ok := ctx.Module().(*Module)
+	if library := moduleLibraryInterface(ctx.Module()); library != nil && canBeVersionVariant(m) {
+		if incomingVariation == "latest" {
+			latestVersion := ""
+			versions := library.allStubsVersions()
+			if len(versions) > 0 {
+				latestVersion = versions[len(versions)-1]
+			}
+			return latestVersion
 		}
+		return incomingVariation
+	} else if ok && m.SplitPerApiLevel() && m.IsSdkVariant() {
+		// If this module only has variants with versions and the incoming dependency doesn't specify which one
+		// is needed then assume the latest version.
+		if incomingVariation == "" {
+			return android.FutureApiLevel.String()
+		}
+		return incomingVariation
+	}
+
+	return ""
+}
+
+func (versionTransitionMutator) Mutate(ctx android.BottomUpMutatorContext, variation string) {
+	// Optimization: return early if this module can't be affected.
+	if ctx.Os() != android.Android {
+		return
+	}
+
+	m, ok := ctx.Module().(*Module)
+	if library := moduleLibraryInterface(ctx.Module()); library != nil && canBeVersionVariant(m) {
+		isLLNDK := m.IsLlndk()
+		isVendorPublicLibrary := m.IsVendorPublicLibrary()
+		isImportedApiLibrary := m.isImportedApiLibrary()
+
+		if variation != "" || isLLNDK || isVendorPublicLibrary || isImportedApiLibrary {
+			// A stubs or LLNDK stubs variant.
+			if m.sanitize != nil {
+				m.sanitize.Properties.ForceDisable = true
+			}
+			if m.stl != nil {
+				m.stl.Properties.Stl = StringPtr("none")
+			}
+			m.Properties.PreventInstall = true
+			lib := moduleLibraryInterface(m)
+			allStubsVersions := library.allStubsVersions()
+			isLatest := len(allStubsVersions) > 0 && variation == allStubsVersions[len(allStubsVersions)-1]
+			lib.setBuildStubs(isLatest)
+		}
+		if variation != "" {
+			// A non-LLNDK stubs module is hidden from make
+			library.setStubsVersion(variation)
+			m.Properties.HideFromMake = true
+		} else {
+			// A non-LLNDK implementation module has a dependency to all stubs versions
+			for _, version := range library.allStubsVersions() {
+				ctx.AddVariationDependencies([]blueprint.Variation{{"version", version}},
+					stubImplDepTag, ctx.ModuleName())
+			}
+		}
+	} else if ok && m.SplitPerApiLevel() && m.IsSdkVariant() {
+		m.Properties.Sdk_version = StringPtr(variation)
+		m.Properties.Min_sdk_version = StringPtr(variation)
 	}
 }
 
diff --git a/cc/library_stub.go b/cc/library_stub.go
index 6f06333..6367825 100644
--- a/cc/library_stub.go
+++ b/cc/library_stub.go
@@ -303,7 +303,7 @@
 	return d.hasApexStubs()
 }
 
-func (d *apiLibraryDecorator) stubsVersions(ctx android.BaseMutatorContext) []string {
+func (d *apiLibraryDecorator) stubsVersions(ctx android.BaseModuleContext) []string {
 	m, ok := ctx.Module().(*Module)
 
 	if !ok {
diff --git a/cc/ndk_library.go b/cc/ndk_library.go
index f326068..b822e5c 100644
--- a/cc/ndk_library.go
+++ b/cc/ndk_library.go
@@ -133,7 +133,7 @@
 	return strings.TrimSuffix(name, ndkLibrarySuffix)
 }
 
-func ndkLibraryVersions(ctx android.BaseMutatorContext, from android.ApiLevel) []string {
+func ndkLibraryVersions(ctx android.BaseModuleContext, from android.ApiLevel) []string {
 	var versions []android.ApiLevel
 	versionStrs := []string{}
 	for _, version := range ctx.Config().AllSupportedApiLevels() {
@@ -147,7 +147,7 @@
 	return versionStrs
 }
 
-func (this *stubDecorator) stubsVersions(ctx android.BaseMutatorContext) []string {
+func (this *stubDecorator) stubsVersions(ctx android.BaseModuleContext) []string {
 	if !ctx.Module().Enabled(ctx) {
 		return nil
 	}
diff --git a/cc/sdk.go b/cc/sdk.go
index 4925ce1..dc1261d 100644
--- a/cc/sdk.go
+++ b/cc/sdk.go
@@ -19,12 +19,86 @@
 	"android/soong/genrule"
 )
 
-// sdkMutator sets a creates a platform and an SDK variant for modules
+// sdkTransitionMutator creates a platform and an SDK variant for modules
 // that set sdk_version, and ignores sdk_version for the platform
 // variant.  The SDK variant will be used for embedding in APKs
 // that may be installed on older platforms.  Apexes use their own
 // variants that enforce backwards compatibility.
-func sdkMutator(ctx android.BottomUpMutatorContext) {
+type sdkTransitionMutator struct{}
+
+func (sdkTransitionMutator) Split(ctx android.BaseModuleContext) []string {
+	if ctx.Os() != android.Android {
+		return []string{""}
+	}
+
+	switch m := ctx.Module().(type) {
+	case LinkableInterface:
+		if m.AlwaysSdk() {
+			if !m.UseSdk() && !m.SplitPerApiLevel() {
+				ctx.ModuleErrorf("UseSdk() must return true when AlwaysSdk is set, did the factory forget to set Sdk_version?")
+			}
+			return []string{"sdk"}
+		} else if m.UseSdk() || m.SplitPerApiLevel() {
+			return []string{"", "sdk"}
+		} else {
+			return []string{""}
+		}
+	case *genrule.Module:
+		if p, ok := m.Extra.(*GenruleExtraProperties); ok {
+			if String(p.Sdk_version) != "" {
+				return []string{"", "sdk"}
+			} else {
+				return []string{""}
+			}
+		}
+	case *CcApiVariant:
+		ccApiVariant, _ := ctx.Module().(*CcApiVariant)
+		if String(ccApiVariant.properties.Variant) == "ndk" {
+			return []string{"sdk"}
+		} else {
+			return []string{""}
+		}
+	}
+
+	return []string{""}
+}
+
+func (sdkTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
+	return sourceVariation
+}
+
+func (sdkTransitionMutator) IncomingTransition(ctx android.IncomingTransitionContext, incomingVariation string) string {
+	if ctx.Os() != android.Android {
+		return ""
+	}
+	switch m := ctx.Module().(type) {
+	case LinkableInterface:
+		if m.AlwaysSdk() {
+			return "sdk"
+		} else if m.UseSdk() || m.SplitPerApiLevel() {
+			return incomingVariation
+		}
+	case *genrule.Module:
+		if p, ok := m.Extra.(*GenruleExtraProperties); ok {
+			if String(p.Sdk_version) != "" {
+				return incomingVariation
+			}
+		}
+	case *CcApiVariant:
+		ccApiVariant, _ := ctx.Module().(*CcApiVariant)
+		if String(ccApiVariant.properties.Variant) == "ndk" {
+			return "sdk"
+		}
+	}
+
+	if ctx.IsAddingDependency() {
+		return incomingVariation
+	} else {
+		return ""
+	}
+}
+
+func (sdkTransitionMutator) Mutate(ctx android.BottomUpMutatorContext, variation string) {
 	if ctx.Os() != android.Android {
 		return
 	}
@@ -33,59 +107,45 @@
 	case LinkableInterface:
 		ccModule, isCcModule := ctx.Module().(*Module)
 		if m.AlwaysSdk() {
-			if !m.UseSdk() && !m.SplitPerApiLevel() {
-				ctx.ModuleErrorf("UseSdk() must return true when AlwaysSdk is set, did the factory forget to set Sdk_version?")
+			if variation != "sdk" {
+				ctx.ModuleErrorf("tried to create variation %q for module with AlwaysSdk set, expected \"sdk\"", variation)
 			}
-			modules := ctx.CreateVariations("sdk")
-			modules[0].(*Module).Properties.IsSdkVariant = true
+
+			ccModule.Properties.IsSdkVariant = true
 		} else if m.UseSdk() || m.SplitPerApiLevel() {
-			modules := ctx.CreateVariations("", "sdk")
+			if variation == "" {
+				// Clear the sdk_version property for the platform (non-SDK) variant so later code
+				// doesn't get confused by it.
+				ccModule.Properties.Sdk_version = nil
+			} else {
+				// Mark the SDK variant.
+				ccModule.Properties.IsSdkVariant = true
 
-			// Clear the sdk_version property for the platform (non-SDK) variant so later code
-			// doesn't get confused by it.
-			modules[0].(*Module).Properties.Sdk_version = nil
-
-			// Mark the SDK variant.
-			modules[1].(*Module).Properties.IsSdkVariant = true
+				// SDK variant never gets installed because the variant is to be embedded in
+				// APKs, not to be installed to the platform.
+				ccModule.Properties.PreventInstall = true
+			}
 
 			if ctx.Config().UnbundledBuildApps() {
-				// For an unbundled apps build, hide the platform variant from Make
-				// so that other Make modules don't link against it, but against the
-				// SDK variant.
-				modules[0].(*Module).Properties.HideFromMake = true
+				if variation == "" {
+					// For an unbundled apps build, hide the platform variant from Make
+					// so that other Make modules don't link against it, but against the
+					// SDK variant.
+					ccModule.Properties.HideFromMake = true
+				}
 			} else {
-				// For a platform build, mark the SDK variant so that it gets a ".sdk" suffix when
-				// exposed to Make.
-				modules[1].(*Module).Properties.SdkAndPlatformVariantVisibleToMake = true
+				if variation == "sdk" {
+					// For a platform build, mark the SDK variant so that it gets a ".sdk" suffix when
+					// exposed to Make.
+					ccModule.Properties.SdkAndPlatformVariantVisibleToMake = true
+				}
 			}
-			// SDK variant never gets installed because the variant is to be embedded in
-			// APKs, not to be installed to the platform.
-			modules[1].(*Module).Properties.PreventInstall = true
-			ctx.AliasVariation("")
 		} else {
 			if isCcModule {
 				// Clear the sdk_version property for modules that don't have an SDK variant so
 				// later code doesn't get confused by it.
 				ccModule.Properties.Sdk_version = nil
 			}
-			ctx.CreateVariations("")
-			ctx.AliasVariation("")
-		}
-	case *genrule.Module:
-		if p, ok := m.Extra.(*GenruleExtraProperties); ok {
-			if String(p.Sdk_version) != "" {
-				ctx.CreateVariations("", "sdk")
-			} else {
-				ctx.CreateVariations("")
-			}
-			ctx.AliasVariation("")
-		}
-	case *CcApiVariant:
-		ccApiVariant, _ := ctx.Module().(*CcApiVariant)
-		if String(ccApiVariant.properties.Variant) == "ndk" {
-			ctx.CreateVariations("sdk")
-		} else {
-			ctx.CreateVariations("")
 		}
 	}
 }
diff --git a/cmd/release_config/release_config_lib/flag_declaration.go b/cmd/release_config/release_config_lib/flag_declaration.go
index 97d4d4c..22001bf 100644
--- a/cmd/release_config/release_config_lib/flag_declaration.go
+++ b/cmd/release_config/release_config_lib/flag_declaration.go
@@ -18,10 +18,21 @@
 	rc_proto "android/soong/cmd/release_config/release_config_proto"
 )
 
+var (
+	// Allowlist: these flags may have duplicate (identical) declarations
+	// without generating an error.  This will be removed once all such
+	// declarations have been fixed.
+	DuplicateDeclarationAllowlist = map[string]bool{}
+)
+
 func FlagDeclarationFactory(protoPath string) (fd *rc_proto.FlagDeclaration) {
 	fd = &rc_proto.FlagDeclaration{}
 	if protoPath != "" {
 		LoadMessage(protoPath, fd)
 	}
+	// If the input didn't specify a value, create one (== UnspecifiedValue).
+	if fd.Value == nil {
+		fd.Value = &rc_proto.Value{Val: &rc_proto.Value_UnspecifiedValue{false}}
+	}
 	return fd
 }
diff --git a/cmd/release_config/release_config_lib/release_configs.go b/cmd/release_config/release_config_lib/release_configs.go
index f2e1388..97eb8f1 100644
--- a/cmd/release_config/release_config_lib/release_configs.go
+++ b/cmd/release_config/release_config_lib/release_configs.go
@@ -42,6 +42,10 @@
 
 	// Flags declared this directory's flag_declarations/*.textproto
 	FlagDeclarations []rc_proto.FlagDeclaration
+
+	// Potential aconfig and build flag contributions in this map directory.
+	// This is used to detect errors.
+	FlagValueDirs map[string][]string
 }
 
 type ReleaseConfigDirMap map[string]int
@@ -272,6 +276,20 @@
 		configs.Aliases[name] = alias.Target
 	}
 	var err error
+	// Temporarily allowlist duplicate flag declaration files to prevent
+	// more from entering the tree while we work to clean up the duplicates
+	// that already exist.
+	dupFlagFile := filepath.Join(dir, "duplicate_allowlist.txt")
+	data, err := os.ReadFile(dupFlagFile)
+	if err == nil {
+		for _, flag := range strings.Split(string(data), "\n") {
+			flag = strings.TrimSpace(flag)
+			if strings.HasPrefix(flag, "//") || strings.HasPrefix(flag, "#") {
+				continue
+			}
+			DuplicateDeclarationAllowlist[flag] = true
+		}
+	}
 	err = WalkTextprotoFiles(dir, "flag_declarations", func(path string, d fs.DirEntry, err error) error {
 		flagDeclaration := FlagDeclarationFactory(path)
 		// Container must be specified.
@@ -285,14 +303,6 @@
 			}
 		}
 
-		// TODO: once we have namespaces initialized, we can throw an error here.
-		if flagDeclaration.Namespace == nil {
-			flagDeclaration.Namespace = proto.String("android_UNKNOWN")
-		}
-		// If the input didn't specify a value, create one (== UnspecifiedValue).
-		if flagDeclaration.Value == nil {
-			flagDeclaration.Value = &rc_proto.Value{Val: &rc_proto.Value_UnspecifiedValue{false}}
-		}
 		m.FlagDeclarations = append(m.FlagDeclarations, *flagDeclaration)
 		name := *flagDeclaration.Name
 		if name == "RELEASE_ACONFIG_VALUE_SETS" {
@@ -300,8 +310,8 @@
 		}
 		if def, ok := configs.FlagArtifacts[name]; !ok {
 			configs.FlagArtifacts[name] = &FlagArtifact{FlagDeclaration: flagDeclaration, DeclarationIndex: ConfigDirIndex}
-		} else if !proto.Equal(def.FlagDeclaration, flagDeclaration) {
-			return fmt.Errorf("Duplicate definition of %s", *flagDeclaration.Name)
+		} else if !proto.Equal(def.FlagDeclaration, flagDeclaration) || !DuplicateDeclarationAllowlist[name] {
+			return fmt.Errorf("Duplicate definition of %s in %s", *flagDeclaration.Name, path)
 		}
 		// Set the initial value in the flag artifact.
 		configs.FilesUsedMap[path] = true
@@ -317,6 +327,21 @@
 		return err
 	}
 
+	subDirs := func(subdir string) (ret []string) {
+		if flagVersions, err := os.ReadDir(filepath.Join(dir, subdir)); err == nil {
+			for _, e := range flagVersions {
+				if e.IsDir() && validReleaseConfigName(e.Name()) {
+					ret = append(ret, e.Name())
+				}
+			}
+		}
+		return
+	}
+	m.FlagValueDirs = map[string][]string{
+		"aconfig":     subDirs("aconfig"),
+		"flag_values": subDirs("flag_values"),
+	}
+
 	err = WalkTextprotoFiles(dir, "release_configs", func(path string, d fs.DirEntry, err error) error {
 		releaseConfigContribution := &ReleaseConfigContribution{path: path, DeclarationIndex: ConfigDirIndex}
 		LoadMessage(path, &releaseConfigContribution.proto)
@@ -424,6 +449,27 @@
 		}
 	}
 
+	// Look for ignored flagging values.  Gather the entire list to make it easier to fix them.
+	errors := []string{}
+	for _, contrib := range configs.ReleaseConfigMaps {
+		dirName := filepath.Dir(contrib.path)
+		for k, names := range contrib.FlagValueDirs {
+			for _, rcName := range names {
+				if config, err := configs.GetReleaseConfig(rcName); err == nil {
+					rcPath := filepath.Join(dirName, "release_configs", fmt.Sprintf("%s.textproto", config.Name))
+					if _, err := os.Stat(rcPath); err != nil {
+						errors = append(errors, fmt.Sprintf("%s exists but %s does not contribute to %s",
+							filepath.Join(dirName, k, rcName), dirName, config.Name))
+					}
+				}
+
+			}
+		}
+	}
+	if len(errors) > 0 {
+		return fmt.Errorf("%s", strings.Join(errors, "\n"))
+	}
+
 	releaseConfig, err := configs.GetReleaseConfig(targetRelease)
 	if err != nil {
 		return err
diff --git a/cmd/release_config/release_config_lib/util.go b/cmd/release_config/release_config_lib/util.go
index 9919c70..b149293 100644
--- a/cmd/release_config/release_config_lib/util.go
+++ b/cmd/release_config/release_config_lib/util.go
@@ -31,8 +31,9 @@
 )
 
 var (
-	disableWarnings    bool
-	containerRegexp, _ = regexp.Compile("^[a-z][a-z0-9]*([._][a-z][a-z0-9]*)*$")
+	disableWarnings        bool
+	containerRegexp, _     = regexp.Compile("^[a-z][a-z0-9]*([._][a-z][a-z0-9]*)*$")
+	releaseConfigRegexp, _ = regexp.Compile("^[a-z][a-z0-9]*([._][a-z0-9]*)*$")
 )
 
 type StringList []string
@@ -179,6 +180,10 @@
 	return containerRegexp.MatchString(container)
 }
 
+func validReleaseConfigName(name string) bool {
+	return releaseConfigRegexp.MatchString(name)
+}
+
 // Returns the default value for release config artifacts.
 func GetDefaultOutDir() string {
 	outEnv := os.Getenv("OUT_DIR")
diff --git a/dexpreopt/dexpreopt.go b/dexpreopt/dexpreopt.go
index 201515f..b69a76f 100644
--- a/dexpreopt/dexpreopt.go
+++ b/dexpreopt/dexpreopt.go
@@ -532,7 +532,7 @@
 	}
 
 	for _, f := range global.PatternsOnSystemOther {
-		if makefileMatch("/" + f, dexLocation) || makefileMatch(filepath.Join(SystemPartition, f), dexLocation) {
+		if makefileMatch("/"+f, dexLocation) || makefileMatch(filepath.Join(SystemPartition, f), dexLocation) {
 			return true
 		}
 	}
diff --git a/docs/resources.md b/docs/resources.md
new file mode 100644
index 0000000..c7cb0cf
--- /dev/null
+++ b/docs/resources.md
@@ -0,0 +1,89 @@
+## Soong Android Resource Compilation
+
+The Android build process involves several steps to compile resources into a format that the Android app can use
+efficiently in android_library, android_app and android_test modules.  See the
+[resources documentation](https://developer.android.com/guide/topics/resources/providing-resources) for general
+information on resources (with a focus on building with Gradle).
+
+For all modules, AAPT2 compiles resources provided by directories listed in the resource_dirs directory (which is
+implicitly set to `["res"]` if unset, but can be overridden by setting the `resource_dirs` property).
+
+## android_library with resource processor
+For an android_library with resource processor enabled (currently by setting `use_resource_processor: true`, but will be
+enabled by default in the future):
+- AAPT2 generates the `package-res.apk` file with a resource table that contains all resources from the current
+android_library module.  `package-res.apk` files from transitive dependencies are passed to AAPT2 with the `-I` flag to
+resolve references to resources from dependencies.
+- AAPT2 generates an R.txt file that lists all the resources provided by the current android_library module.
+- ResourceProcessorBusyBox reads the `R.txt` file for the current android_library and produces an `R.jar` with an
+`R.class` in the package listed in the android_library's `AndroidManifest.xml` file that contains java fields for each
+resource ID.  The resource IDs are non-final, as the final IDs will not be known until the resource table of the final
+android_app or android_test module is built.
+- The android_library's java and/or kotlin code is compiled with the generated `R.jar` in the classpath, along with the
+`R.jar` files from all transitive android_library dependencies.
+
+## android_app or android_test with resource processor
+For an android_app or android_test with resource processor enabled (currently by setting `use_resource_processor: true`,
+but will be enabled by default in the future):
+- AAPT2 generates the `package-res.apk` file with a resource table that contains all resources from the current
+android_app or android_test, as well as all transitive android_library modules referenced via `static_libs`.  The
+current module is overlaid on dependencies so that resources from the current module replace resources from dependencies
+in the case of conflicts.
+- AAPT2 generates an R.txt file that lists all the resources provided by the current android_app or android_test, as
+well as all transitive android_library modules referenced via `static_libs`.  The R.txt file contains the final resource
+ID for each resource.
+- ResourceProcessorBusyBox reads the `R.txt` file for the current android_app or android_test, as well as all transitive
+android_library modules referenced via `static_libs`, and produces an `R.jar` with an `R.class` in the package listed in
+the android_app or android_test's `AndroidManifest.xml` file that contains java fields for all local or transitive
+resource IDs.  In addition, it creates an `R.class` in the package listed in each android_library dependency's
+`AndroidManifest.xml` file that contains final resource IDs for the resources that were found in that library.
+- The android_app or android_test's java and/or kotlin code is compiled with the current module's `R.jar` in the
+classpath, but not the `R.jar` files from transitive android_library dependencies.  The `R.jar` file is also merged into
+the program  classes that are dexed and placed in the final APK.
+
+## android_app, android_test or android_library without resource processor
+For an android_app, android_test or android_library without resource processor enabled (current the default, or
+explicitly set with `use_resource_processor: false`):
+- AAPT2 generates the `package-res.apk` file with a resource table that contains all resources from the current
+android_app, android_test or android_library module, as well as all transitive android_library modules referenced via
+`static_libs`.  The current module is overlaid on dependencies so that resources from the current module replace
+resources from dependencies in the case of conflicts.
+- AAPT2 generates an `R.java` file in the package listed in each the current module's `AndroidManifest.xml` file that
+contains resource IDs for all resources from the current module as well as all transitive android_library modules
+referenced via `static_libs`.  The same `R.java` containing all local and transitive resources is also duplicated into
+every package listed in an `AndroidManifest.xml` file in any static `android_library` dependency.
+- The module's java and/or kotlin code is compiled along with all the generated `R.java` files.
+
+
+## Downsides of legacy resource compilation without resource processor
+
+Compiling resources without using the resource processor results in a generated R.java source file for every transitive
+package that contains every transitive resource.  For modules with large transitive dependency trees this can be tens of
+thousands of resource IDs duplicated in tens to a hundred java sources.  These java sources all have to be compiled in
+every successive module in the dependency tree, and then the final R8 step has to drop hundreds of thousands of
+unreferenced fields.  This results in significant build time and disk usage increases over building with resource
+processor.
+
+## Converting to compilation with resource processor
+
+### Reference resources using the package name of the module that includes them.
+Converting an android_library module to build with resource processor requires fixing any references to resources
+provided by android_library dependencies to reference the R classes using the package name found in the
+`AndroidManifest.xml` file of the dependency.  For example, when referencing an androidx resource:
+```java
+View.inflate(mContext, R.layout.preference, null));
+```
+must be replaced with:
+```java
+View.inflate(mContext, androidx.preference.R.layout.preference, null));
+```
+
+### Use unique package names for each module in `AndroidManifest.xml`
+
+Each module will produce an `R.jar` containing an `R.class` in the package specified in it's `AndroidManifest.xml`.
+If multiple modules use the same package name they will produce conflicting `R.class` files, which can cause some
+resource IDs to appear to be missing.
+
+If existing code has multiple modules that contribute resources to the same package, one option is to move all the
+resources into a single resources-only `android_library` module with no code, and then depend on that from all the other
+modules.
\ No newline at end of file
diff --git a/elf/Android.bp b/elf/Android.bp
index 6450be1..6d3f4f0 100644
--- a/elf/Android.bp
+++ b/elf/Android.bp
@@ -20,6 +20,7 @@
     name: "soong-elf",
     pkgPath: "android/soong/elf",
     srcs: [
+        "build_id_dir.go",
         "elf.go",
     ],
     testSrcs: [
diff --git a/elf/build_id_dir.go b/elf/build_id_dir.go
new file mode 100644
index 0000000..5fb7dda
--- /dev/null
+++ b/elf/build_id_dir.go
@@ -0,0 +1,172 @@
+// Copyright 2024 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package elf
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+)
+
+func UpdateBuildIdDir(path string) error {
+	path = filepath.Clean(path)
+	buildIdPath := path + "/.build-id"
+
+	// Collect the list of files and build-id symlinks. If the symlinks are
+	// up to date (newer than the symbol files), there is nothing to do.
+	var buildIdFiles, symbolFiles []string
+	var buildIdMtime, symbolsMtime time.Time
+	filepath.WalkDir(path, func(path string, entry fs.DirEntry, err error) error {
+		if entry == nil || entry.IsDir() {
+			return nil
+		}
+		info, err := entry.Info()
+		if err != nil {
+			return err
+		}
+		mtime := info.ModTime()
+		if strings.HasPrefix(path, buildIdPath) {
+			if buildIdMtime.Compare(mtime) < 0 {
+				buildIdMtime = mtime
+			}
+			buildIdFiles = append(buildIdFiles, path)
+		} else {
+			if symbolsMtime.Compare(mtime) < 0 {
+				symbolsMtime = mtime
+			}
+			symbolFiles = append(symbolFiles, path)
+		}
+		return nil
+	})
+	if symbolsMtime.Compare(buildIdMtime) < 0 {
+		return nil
+	}
+
+	// Collect build-id -> file mapping from ELF files in the symbols directory.
+	concurrency := 8
+	done := make(chan error)
+	buildIdToFile := make(map[string]string)
+	var mu sync.Mutex
+	for i := 0; i != concurrency; i++ {
+		go func(paths []string) {
+			for _, path := range paths {
+				id, err := Identifier(path, true)
+				if err != nil {
+					done <- err
+					return
+				}
+				if id == "" {
+					continue
+				}
+				mu.Lock()
+				oldPath := buildIdToFile[id]
+				if oldPath == "" || oldPath > path {
+					buildIdToFile[id] = path
+				}
+				mu.Unlock()
+			}
+			done <- nil
+		}(symbolFiles[len(symbolFiles)*i/concurrency : len(symbolFiles)*(i+1)/concurrency])
+	}
+
+	// Collect previously generated build-id -> file mapping from the .build-id directory.
+	// We will use this for incremental updates. If we see anything in the .build-id
+	// directory that we did not expect, we'll delete it and start over.
+	prevBuildIdToFile := make(map[string]string)
+out:
+	for _, buildIdFile := range buildIdFiles {
+		if !strings.HasSuffix(buildIdFile, ".debug") {
+			prevBuildIdToFile = nil
+			break
+		}
+		buildId := buildIdFile[len(buildIdPath)+1 : len(buildIdFile)-6]
+		for i, ch := range buildId {
+			if i == 2 {
+				if ch != '/' {
+					prevBuildIdToFile = nil
+					break out
+				}
+			} else {
+				if (ch < '0' || ch > '9') && (ch < 'a' || ch > 'f') {
+					prevBuildIdToFile = nil
+					break out
+				}
+			}
+		}
+		target, err := os.Readlink(buildIdFile)
+		if err != nil || !strings.HasPrefix(target, "../../") {
+			prevBuildIdToFile = nil
+			break
+		}
+		prevBuildIdToFile[buildId[0:2]+buildId[3:]] = path + target[5:]
+	}
+	if prevBuildIdToFile == nil {
+		err := os.RemoveAll(buildIdPath)
+		if err != nil {
+			return err
+		}
+		prevBuildIdToFile = make(map[string]string)
+	}
+
+	// Wait for build-id collection from ELF files to finish.
+	for i := 0; i != concurrency; i++ {
+		err := <-done
+		if err != nil {
+			return err
+		}
+	}
+
+	// Delete old symlinks.
+	for id, _ := range prevBuildIdToFile {
+		if buildIdToFile[id] == "" {
+			symlinkDir := buildIdPath + "/" + id[:2]
+			symlinkPath := symlinkDir + "/" + id[2:] + ".debug"
+			if err := os.Remove(symlinkPath); err != nil {
+				return err
+			}
+		}
+	}
+
+	// Add new symlinks and update changed symlinks.
+	for id, path := range buildIdToFile {
+		prevPath := prevBuildIdToFile[id]
+		if prevPath == path {
+			continue
+		}
+		symlinkDir := buildIdPath + "/" + id[:2]
+		symlinkPath := symlinkDir + "/" + id[2:] + ".debug"
+		if prevPath == "" {
+			if err := os.MkdirAll(symlinkDir, 0755); err != nil {
+				return err
+			}
+		} else {
+			if err := os.Remove(symlinkPath); err != nil {
+				return err
+			}
+		}
+
+		target, err := filepath.Rel(symlinkDir, path)
+		if err != nil {
+			return err
+		}
+		if err := os.Symlink(target, symlinkPath); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/etc/prebuilt_etc.go b/etc/prebuilt_etc.go
index d04b2d1..fc6d1f7 100644
--- a/etc/prebuilt_etc.go
+++ b/etc/prebuilt_etc.go
@@ -126,6 +126,15 @@
 	Relative_install_path *string `android:"arch_variant"`
 }
 
+type prebuiltRootProperties struct {
+	// Install this module to the root directory, without partition subdirs.  When this module is
+	// added to PRODUCT_PACKAGES, this module will be installed to $PRODUCT_OUT/root, which will
+	// then be copied to the root of system.img. When this module is packaged by other modules like
+	// android_filesystem, this module will be installed to the root ("/"), unlike normal
+	// prebuilt_root modules which are installed to the partition subdir (e.g. "/system/").
+	Install_in_root *bool
+}
+
 type PrebuiltEtcModule interface {
 	android.Module
 
@@ -140,7 +149,12 @@
 	android.ModuleBase
 	android.DefaultableModuleBase
 
-	properties       prebuiltEtcProperties
+	properties prebuiltEtcProperties
+
+	// rootProperties is used to return the value of the InstallInRoot() method. Currently, only
+	// prebuilt_avb and prebuilt_root modules use this.
+	rootProperties prebuiltRootProperties
+
 	subdirProperties prebuiltSubdirProperties
 
 	sourceFilePaths android.Paths
@@ -156,9 +170,6 @@
 	additionalDependencies *android.Paths
 
 	usedSrcsProperty bool
-	// installInRoot is used to return the value of the InstallInRoot() method. The default value is false.
-	// Currently, only prebuilt_avb can be set to true.
-	installInRoot bool
 
 	makeClass string
 }
@@ -246,7 +257,7 @@
 }
 
 func (p *PrebuiltEtc) InstallInRoot() bool {
-	return p.installInRoot
+	return proptools.Bool(p.rootProperties.Install_in_root)
 }
 
 func (p *PrebuiltEtc) RecoveryVariantNeeded(ctx android.BaseModuleContext) bool {
@@ -502,21 +513,20 @@
 
 func InitPrebuiltEtcModule(p *PrebuiltEtc, dirBase string) {
 	p.installDirBase = dirBase
-	p.installInRoot = false
 	p.AddProperties(&p.properties)
 	p.AddProperties(&p.subdirProperties)
 }
 
 func InitPrebuiltRootModule(p *PrebuiltEtc) {
 	p.installDirBase = "."
-	p.installInRoot = false
 	p.AddProperties(&p.properties)
+	p.AddProperties(&p.rootProperties)
 }
 
 func InitPrebuiltAvbModule(p *PrebuiltEtc) {
 	p.installDirBase = "avb"
-	p.installInRoot = true
 	p.AddProperties(&p.properties)
+	p.rootProperties.Install_in_root = proptools.BoolPtr(true)
 }
 
 // prebuilt_etc is for a prebuilt artifact that is installed in
diff --git a/filesystem/filesystem.go b/filesystem/filesystem.go
index 5add954..5c7ef43 100644
--- a/filesystem/filesystem.go
+++ b/filesystem/filesystem.go
@@ -312,6 +312,25 @@
 	}
 }
 
+func (f *filesystem) copyPackagingSpecs(ctx android.ModuleContext, builder *android.RuleBuilder, specs map[string]android.PackagingSpec, rootDir, rebasedDir android.WritablePath) []string {
+	rootDirSpecs := make(map[string]android.PackagingSpec)
+	rebasedDirSpecs := make(map[string]android.PackagingSpec)
+
+	for rel, spec := range specs {
+		if spec.Partition() == "root" {
+			rootDirSpecs[rel] = spec
+		} else {
+			rebasedDirSpecs[rel] = spec
+		}
+	}
+
+	dirsToSpecs := make(map[android.WritablePath]map[string]android.PackagingSpec)
+	dirsToSpecs[rootDir] = rootDirSpecs
+	dirsToSpecs[rebasedDir] = rebasedDirSpecs
+
+	return f.CopySpecsToDirs(ctx, builder, dirsToSpecs)
+}
+
 func (f *filesystem) buildImageUsingBuildImage(ctx android.ModuleContext) android.OutputPath {
 	rootDir := android.PathForModuleOut(ctx, "root").OutputPath
 	rebasedDir := rootDir
@@ -322,7 +341,7 @@
 	// Wipe the root dir to get rid of leftover files from prior builds
 	builder.Command().Textf("rm -rf %s && mkdir -p %s", rootDir, rootDir)
 	specs := f.gatherFilteredPackagingSpecs(ctx)
-	f.entries = f.CopySpecsToDir(ctx, builder, specs, rebasedDir)
+	f.entries = f.copyPackagingSpecs(ctx, builder, specs, rootDir, rebasedDir)
 
 	f.buildNonDepsFiles(ctx, builder, rootDir)
 	f.addMakeBuiltFiles(ctx, builder, rootDir)
@@ -465,7 +484,7 @@
 	// Wipe the root dir to get rid of leftover files from prior builds
 	builder.Command().Textf("rm -rf %s && mkdir -p %s", rootDir, rootDir)
 	specs := f.gatherFilteredPackagingSpecs(ctx)
-	f.entries = f.CopySpecsToDir(ctx, builder, specs, rebasedDir)
+	f.entries = f.copyPackagingSpecs(ctx, builder, specs, rootDir, rebasedDir)
 
 	f.buildNonDepsFiles(ctx, builder, rootDir)
 	f.buildFsverityMetadataFiles(ctx, builder, specs, rootDir, rebasedDir)
diff --git a/filesystem/system_image.go b/filesystem/system_image.go
index 15cacfb..69d922d 100644
--- a/filesystem/system_image.go
+++ b/filesystem/system_image.go
@@ -94,9 +94,10 @@
 	return output
 }
 
-// Filter the result of GatherPackagingSpecs to discard items targeting outside "system" partition.
-// Note that "apex" module installs its contents to "apex"(fake partition) as well
+// Filter the result of GatherPackagingSpecs to discard items targeting outside "system" / "root"
+// partition.  Note that "apex" module installs its contents to "apex"(fake partition) as well
 // for symbol lookup by imitating "activated" paths.
 func (s *systemImage) filterPackagingSpec(ps android.PackagingSpec) bool {
-	return s.filesystem.filterInstallablePackagingSpec(ps) && ps.Partition() == "system"
+	return s.filesystem.filterInstallablePackagingSpec(ps) &&
+		(ps.Partition() == "system" || ps.Partition() == "root")
 }
diff --git a/java/Android.bp b/java/Android.bp
index 54b36ab..a941754 100644
--- a/java/Android.bp
+++ b/java/Android.bp
@@ -87,6 +87,7 @@
         "app_set_test.go",
         "app_test.go",
         "code_metadata_test.go",
+        "container_test.go",
         "bootclasspath_fragment_test.go",
         "device_host_converter_test.go",
         "dex_test.go",
diff --git a/java/aapt2.go b/java/aapt2.go
index f704fc6..61cf373 100644
--- a/java/aapt2.go
+++ b/java/aapt2.go
@@ -69,7 +69,7 @@
 
 // aapt2Compile compiles resources and puts the results in the requested directory.
 func aapt2Compile(ctx android.ModuleContext, dir android.Path, paths android.Paths,
-	flags []string, productToFilter string) android.WritablePaths {
+	flags []string, productToFilter string, featureFlagsPaths android.Paths) android.WritablePaths {
 	if productToFilter != "" && productToFilter != "default" {
 		// --filter-product leaves only product-specific resources. Product-specific resources only exist
 		// in value resources (values/*.xml), so filter value resource files only. Ignore other types of
@@ -85,6 +85,10 @@
 		flags = append([]string{"--filter-product " + productToFilter}, flags...)
 	}
 
+	for _, featureFlagsPath := range android.SortedUniquePaths(featureFlagsPaths) {
+		flags = append(flags, "--feature-flags", "@"+featureFlagsPath.String())
+	}
+
 	// Shard the input paths so that they can be processed in parallel. If we shard them into too
 	// small chunks, the additional cost of spinning up aapt2 outweighs the performance gain. The
 	// current shard size, 100, seems to be a good balance between the added cost and the gain.
@@ -112,6 +116,7 @@
 		ctx.Build(pctx, android.BuildParams{
 			Rule:        aapt2CompileRule,
 			Description: "aapt2 compile " + dir.String() + shardDesc,
+			Implicits:   featureFlagsPaths,
 			Inputs:      shard,
 			Outputs:     outPaths,
 			Args: map[string]string{
diff --git a/java/aar.go b/java/aar.go
index 2f49a95..b69b7c2 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -440,7 +440,8 @@
 	var compiledResDirs []android.Paths
 	for _, dir := range resDirs {
 		a.resourceFiles = append(a.resourceFiles, dir.files...)
-		compiledResDirs = append(compiledResDirs, aapt2Compile(ctx, dir.dir, dir.files, compileFlags, a.filterProduct()).Paths())
+		compiledResDirs = append(compiledResDirs, aapt2Compile(ctx, dir.dir, dir.files,
+			compileFlags, a.filterProduct(), opts.aconfigTextFiles).Paths())
 	}
 
 	for i, zip := range resZips {
@@ -499,7 +500,8 @@
 	}
 
 	for _, dir := range overlayDirs {
-		compiledOverlay = append(compiledOverlay, aapt2Compile(ctx, dir.dir, dir.files, compileFlags, a.filterProduct()).Paths()...)
+		compiledOverlay = append(compiledOverlay, aapt2Compile(ctx, dir.dir, dir.files,
+			compileFlags, a.filterProduct(), opts.aconfigTextFiles).Paths()...)
 	}
 
 	var splitPackages android.WritablePaths
diff --git a/java/app_test.go b/java/app_test.go
index e878ccf..6b7d522 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -4364,7 +4364,16 @@
 }
 
 func TestAppFlagsPackages(t *testing.T) {
-	ctx := testApp(t, `
+	ctx := android.GroupFixturePreparers(
+		prepareForJavaTest,
+		android.FixtureMergeMockFs(
+			map[string][]byte{
+				"res/layout/layout.xml":         nil,
+				"res/values/strings.xml":        nil,
+				"res/values-en-rUS/strings.xml": nil,
+			},
+		),
+	).RunTestWithBp(t, `
 		android_app {
 			name: "foo",
 			srcs: ["a.java"],
@@ -4396,10 +4405,10 @@
 
 	// android_app module depends on aconfig_declarations listed in flags_packages
 	android.AssertBoolEquals(t, "foo expected to depend on bar", true,
-		CheckModuleHasDependency(t, ctx, "foo", "android_common", "bar"))
+		CheckModuleHasDependency(t, ctx.TestContext, "foo", "android_common", "bar"))
 
 	android.AssertBoolEquals(t, "foo expected to depend on baz", true,
-		CheckModuleHasDependency(t, ctx, "foo", "android_common", "baz"))
+		CheckModuleHasDependency(t, ctx.TestContext, "foo", "android_common", "baz"))
 
 	aapt2LinkRule := foo.Rule("android/soong/java.aapt2Link")
 	linkInFlags := aapt2LinkRule.Args["inFlags"]
@@ -4408,6 +4417,14 @@
 		linkInFlags,
 		"--feature-flags @out/soong/.intermediates/bar/intermediate.txt --feature-flags @out/soong/.intermediates/baz/intermediate.txt",
 	)
+
+	aapt2CompileRule := foo.Rule("android/soong/java.aapt2Compile")
+	compileFlags := aapt2CompileRule.Args["cFlags"]
+	android.AssertStringDoesContain(t,
+		"aapt2 compile command expected to pass feature flags arguments",
+		compileFlags,
+		"--feature-flags @out/soong/.intermediates/bar/intermediate.txt --feature-flags @out/soong/.intermediates/baz/intermediate.txt",
+	)
 }
 
 func TestAppFlagsPackagesPropagation(t *testing.T) {
diff --git a/java/base.go b/java/base.go
index fc68d20..02dc3e3 100644
--- a/java/base.go
+++ b/java/base.go
@@ -552,6 +552,18 @@
 	aconfigCacheFiles android.Paths
 }
 
+var _ android.InstallableModule = (*Module)(nil)
+
+// To satisfy the InstallableModule interface
+func (j *Module) EnforceApiContainerChecks() bool {
+	return true
+}
+
+// Overrides android.ModuleBase.InstallInProduct()
+func (j *Module) InstallInProduct() bool {
+	return j.ProductSpecific()
+}
+
 func (j *Module) CheckStableSdkVersion(ctx android.BaseModuleContext) error {
 	sdkVersion := j.SdkVersion(ctx)
 	if sdkVersion.Stable() {
diff --git a/java/container_test.go b/java/container_test.go
new file mode 100644
index 0000000..3441855
--- /dev/null
+++ b/java/container_test.go
@@ -0,0 +1,129 @@
+// Copyright 2024 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package java
+
+import (
+	"android/soong/android"
+	"fmt"
+	"testing"
+)
+
+var checkContainerMatch = func(t *testing.T, name string, container string, expected bool, actual bool) {
+	errorMessage := fmt.Sprintf("module %s container %s value differ", name, container)
+	android.AssertBoolEquals(t, errorMessage, expected, actual)
+}
+
+func TestJavaContainersModuleProperties(t *testing.T) {
+	result := android.GroupFixturePreparers(
+		prepareForJavaTest,
+	).RunTestWithBp(t, `
+		java_library {
+			name: "foo",
+			srcs: ["A.java"],
+		}
+		java_library {
+			name: "foo_vendor",
+			srcs: ["A.java"],
+			vendor: true,
+			sdk_version: "current",
+		}
+		java_library {
+			name: "foo_soc_specific",
+			srcs: ["A.java"],
+			soc_specific: true,
+			sdk_version: "current",
+		}
+		java_library {
+			name: "foo_product_specific",
+			srcs: ["A.java"],
+			product_specific: true,
+			sdk_version: "current",
+		}
+		java_test {
+			name: "foo_cts_test",
+			srcs: ["A.java"],
+			test_suites: [
+				"cts",
+			],
+		}
+		java_test {
+			name: "foo_non_cts_test",
+			srcs: ["A.java"],
+			test_suites: [
+				"general-tests",
+			],
+		}
+	`)
+
+	testcases := []struct {
+		moduleName         string
+		isSystemContainer  bool
+		isVendorContainer  bool
+		isProductContainer bool
+		isCts              bool
+	}{
+		{
+			moduleName:         "foo",
+			isSystemContainer:  true,
+			isVendorContainer:  false,
+			isProductContainer: false,
+			isCts:              false,
+		},
+		{
+			moduleName:         "foo_vendor",
+			isSystemContainer:  false,
+			isVendorContainer:  true,
+			isProductContainer: false,
+			isCts:              false,
+		},
+		{
+			moduleName:         "foo_soc_specific",
+			isSystemContainer:  false,
+			isVendorContainer:  true,
+			isProductContainer: false,
+			isCts:              false,
+		},
+		{
+			moduleName:         "foo_product_specific",
+			isSystemContainer:  false,
+			isVendorContainer:  false,
+			isProductContainer: true,
+			isCts:              false,
+		},
+		{
+			moduleName:         "foo_cts_test",
+			isSystemContainer:  false,
+			isVendorContainer:  false,
+			isProductContainer: false,
+			isCts:              true,
+		},
+		{
+			moduleName:         "foo_non_cts_test",
+			isSystemContainer:  false,
+			isVendorContainer:  false,
+			isProductContainer: false,
+			isCts:              false,
+		},
+	}
+
+	for _, c := range testcases {
+		m := result.ModuleForTests(c.moduleName, "android_common")
+		containers, _ := android.OtherModuleProvider(result.TestContext.OtherModuleProviderAdaptor(), m.Module(), android.ContainersInfoProvider)
+		belongingContainers := containers.BelongingContainers()
+		checkContainerMatch(t, c.moduleName, "system", c.isSystemContainer, android.InList(android.SystemContainer, belongingContainers))
+		checkContainerMatch(t, c.moduleName, "vendor", c.isVendorContainer, android.InList(android.VendorContainer, belongingContainers))
+		checkContainerMatch(t, c.moduleName, "product", c.isProductContainer, android.InList(android.ProductContainer, belongingContainers))
+	}
+}
diff --git a/java/java.go b/java/java.go
index 88b31b5..498b539 100644
--- a/java/java.go
+++ b/java/java.go
@@ -2386,10 +2386,35 @@
 	return android.FutureApiLevel
 }
 
+func (al *ApiLibrary) IDEInfo(i *android.IdeInfo) {
+	i.Deps = append(i.Deps, al.ideDeps()...)
+	i.Libs = append(i.Libs, al.properties.Libs...)
+	i.Static_libs = append(i.Static_libs, al.properties.Static_libs...)
+	i.SrcJars = append(i.SrcJars, al.stubsSrcJar.String())
+}
+
+// deps of java_api_library for module_bp_java_deps.json
+func (al *ApiLibrary) ideDeps() []string {
+	ret := []string{}
+	ret = append(ret, al.properties.Libs...)
+	ret = append(ret, al.properties.Static_libs...)
+	if al.properties.System_modules != nil {
+		ret = append(ret, proptools.String(al.properties.System_modules))
+	}
+	if al.properties.Full_api_surface_stub != nil {
+		ret = append(ret, proptools.String(al.properties.Full_api_surface_stub))
+	}
+	// Other non java_library dependencies like java_api_contribution are ignored for now.
+	return ret
+}
+
 // implement the following interfaces for hiddenapi processing
 var _ hiddenAPIModule = (*ApiLibrary)(nil)
 var _ UsesLibraryDependency = (*ApiLibrary)(nil)
 
+// implement the following interface for IDE completion.
+var _ android.IDEInfo = (*ApiLibrary)(nil)
+
 //
 // Java prebuilts
 //
diff --git a/python/python.go b/python/python.go
index 1ee533f..8726f02 100644
--- a/python/python.go
+++ b/python/python.go
@@ -38,7 +38,7 @@
 
 // Exported to support other packages using Python modules in tests.
 func RegisterPythonPreDepsMutators(ctx android.RegisterMutatorsContext) {
-	ctx.BottomUp("python_version", versionSplitMutator()).Parallel()
+	ctx.Transition("python_version", &versionSplitTransitionMutator{})
 }
 
 // the version-specific properties that apply to python modules.
@@ -245,7 +245,6 @@
 	protoExt                 = ".proto"
 	pyVersion2               = "PY2"
 	pyVersion3               = "PY3"
-	pyVersion2And3           = "PY2ANDPY3"
 	internalPath             = "internal"
 )
 
@@ -253,46 +252,68 @@
 	getBaseProperties() *BaseProperties
 }
 
-// versionSplitMutator creates version variants for modules and appends the version-specific
-// properties for a given variant to the properties in the variant module
-func versionSplitMutator() func(android.BottomUpMutatorContext) {
-	return func(mctx android.BottomUpMutatorContext) {
-		if base, ok := mctx.Module().(basePropertiesProvider); ok {
-			props := base.getBaseProperties()
-			var versionNames []string
-			// collect version specific properties, so that we can merge version-specific properties
-			// into the module's overall properties
-			var versionProps []VersionProperties
-			// PY3 is first so that we alias the PY3 variant rather than PY2 if both
-			// are available
-			if proptools.BoolDefault(props.Version.Py3.Enabled, true) {
-				versionNames = append(versionNames, pyVersion3)
-				versionProps = append(versionProps, props.Version.Py3)
+type versionSplitTransitionMutator struct{}
+
+func (versionSplitTransitionMutator) Split(ctx android.BaseModuleContext) []string {
+	if base, ok := ctx.Module().(basePropertiesProvider); ok {
+		props := base.getBaseProperties()
+		var variants []string
+		// PY3 is first so that we alias the PY3 variant rather than PY2 if both
+		// are available
+		if proptools.BoolDefault(props.Version.Py3.Enabled, true) {
+			variants = append(variants, pyVersion3)
+		}
+		if proptools.BoolDefault(props.Version.Py2.Enabled, false) {
+			if !ctx.DeviceConfig().BuildBrokenUsesSoongPython2Modules() &&
+				ctx.ModuleName() != "py2-cmd" &&
+				ctx.ModuleName() != "py2-stdlib" {
+				ctx.PropertyErrorf("version.py2.enabled", "Python 2 is no longer supported, please convert to python 3. This error can be temporarily overridden by setting BUILD_BROKEN_USES_SOONG_PYTHON2_MODULES := true in the product configuration")
 			}
-			if proptools.BoolDefault(props.Version.Py2.Enabled, false) {
-				if !mctx.DeviceConfig().BuildBrokenUsesSoongPython2Modules() &&
-					mctx.ModuleName() != "py2-cmd" &&
-					mctx.ModuleName() != "py2-stdlib" {
-					mctx.PropertyErrorf("version.py2.enabled", "Python 2 is no longer supported, please convert to python 3. This error can be temporarily overridden by setting BUILD_BROKEN_USES_SOONG_PYTHON2_MODULES := true in the product configuration")
-				}
-				versionNames = append(versionNames, pyVersion2)
-				versionProps = append(versionProps, props.Version.Py2)
-			}
-			modules := mctx.CreateLocalVariations(versionNames...)
-			// Alias module to the first variant
-			if len(versionNames) > 0 {
-				mctx.AliasVariation(versionNames[0])
-			}
-			for i, v := range versionNames {
-				// set the actual version for Python module.
-				newProps := modules[i].(basePropertiesProvider).getBaseProperties()
-				newProps.Actual_version = v
-				// append versioned properties for the Python module to the overall properties
-				err := proptools.AppendMatchingProperties([]interface{}{newProps}, &versionProps[i], nil)
-				if err != nil {
-					panic(err)
-				}
-			}
+			variants = append(variants, pyVersion2)
+		}
+		return variants
+	}
+	return []string{""}
+}
+
+func (versionSplitTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
+	return ""
+}
+
+func (versionSplitTransitionMutator) IncomingTransition(ctx android.IncomingTransitionContext, incomingVariation string) string {
+	if incomingVariation != "" {
+		return incomingVariation
+	}
+	if base, ok := ctx.Module().(basePropertiesProvider); ok {
+		props := base.getBaseProperties()
+		if proptools.BoolDefault(props.Version.Py3.Enabled, true) {
+			return pyVersion3
+		} else {
+			return pyVersion2
+		}
+	}
+
+	return ""
+}
+
+func (versionSplitTransitionMutator) Mutate(ctx android.BottomUpMutatorContext, variation string) {
+	if variation == "" {
+		return
+	}
+	if base, ok := ctx.Module().(basePropertiesProvider); ok {
+		props := base.getBaseProperties()
+		props.Actual_version = variation
+
+		var versionProps *VersionProperties
+		if variation == pyVersion3 {
+			versionProps = &props.Version.Py3
+		} else if variation == pyVersion2 {
+			versionProps = &props.Version.Py2
+		}
+
+		err := proptools.AppendMatchingProperties([]interface{}{props}, versionProps, nil)
+		if err != nil {
+			panic(err)
 		}
 	}
 }
diff --git a/rust/coverage.go b/rust/coverage.go
index e0e919c..91a7806 100644
--- a/rust/coverage.go
+++ b/rust/coverage.go
@@ -47,7 +47,7 @@
 
 		// no_std modules are missing libprofiler_builtins which provides coverage, so we need to add it as a dependency.
 		if rustModule, ok := ctx.Module().(*Module); ok && rustModule.compiler.noStdlibs() {
-			ctx.AddVariationDependencies([]blueprint.Variation{{Mutator: "rust_libraries", Variation: "rlib"}, {Mutator: "link", Variation: ""}}, rlibDepTag, ProfilerBuiltins)
+			ctx.AddVariationDependencies([]blueprint.Variation{{Mutator: "rust_libraries", Variation: "rlib"}}, rlibDepTag, ProfilerBuiltins)
 		}
 	}
 
diff --git a/rust/library.go b/rust/library.go
index ba73f27..50d5a72 100644
--- a/rust/library.go
+++ b/rust/library.go
@@ -20,6 +20,8 @@
 	"regexp"
 	"strings"
 
+	"github.com/google/blueprint"
+
 	"android/soong/android"
 	"android/soong/cc"
 )
@@ -692,31 +694,28 @@
 	}
 }
 
-// LibraryMutator mutates the libraries into variants according to the
-// build{Rlib,Dylib} attributes.
-func LibraryMutator(mctx android.BottomUpMutatorContext) {
-	// Only mutate on Rust libraries.
-	m, ok := mctx.Module().(*Module)
+type libraryTransitionMutator struct{}
+
+func (libraryTransitionMutator) Split(ctx android.BaseModuleContext) []string {
+	m, ok := ctx.Module().(*Module)
 	if !ok || m.compiler == nil {
-		return
+		return []string{""}
 	}
 	library, ok := m.compiler.(libraryInterface)
 	if !ok {
-		return
+		return []string{""}
 	}
 
 	// Don't produce rlib/dylib/source variants for shared or static variants
 	if library.shared() || library.static() {
-		return
+		return []string{""}
 	}
 
 	var variants []string
 	// The source variant is used for SourceProvider modules. The other variants (i.e. rlib and dylib)
 	// depend on this variant. It must be the first variant to be declared.
-	sourceVariant := false
 	if m.sourceProvider != nil {
-		variants = append(variants, "source")
-		sourceVariant = true
+		variants = append(variants, sourceVariation)
 	}
 	if library.buildRlib() {
 		variants = append(variants, rlibVariation)
@@ -726,92 +725,134 @@
 	}
 
 	if len(variants) == 0 {
-		return
+		return []string{""}
 	}
-	modules := mctx.CreateLocalVariations(variants...)
 
-	// The order of the variations (modules) matches the variant names provided. Iterate
-	// through the new variation modules and set their mutated properties.
-	var emptyVariant = false
-	var rlibVariant = false
-	for i, v := range modules {
-		switch variants[i] {
-		case rlibVariation:
-			v.(*Module).compiler.(libraryInterface).setRlib()
-			rlibVariant = true
-		case dylibVariation:
-			v.(*Module).compiler.(libraryInterface).setDylib()
-			if v.(*Module).ModuleBase.ImageVariation().Variation == android.VendorRamdiskVariation {
-				// TODO(b/165791368)
-				// Disable dylib Vendor Ramdisk variations until we support these.
-				v.(*Module).Disable()
-			}
+	return variants
+}
 
-		case "source":
-			v.(*Module).compiler.(libraryInterface).setSource()
-			// The source variant does not produce any library.
-			// Disable the compilation steps.
-			v.(*Module).compiler.SetDisabled()
-		case "":
-			emptyVariant = true
+func (libraryTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
+	return ""
+}
+
+func (libraryTransitionMutator) IncomingTransition(ctx android.IncomingTransitionContext, incomingVariation string) string {
+	m, ok := ctx.Module().(*Module)
+	if !ok || m.compiler == nil {
+		return ""
+	}
+	library, ok := m.compiler.(libraryInterface)
+	if !ok {
+		return ""
+	}
+
+	if incomingVariation == "" {
+		if m.sourceProvider != nil {
+			return sourceVariation
+		}
+		if library.shared() {
+			return ""
+		}
+		if library.buildRlib() {
+			return rlibVariation
+		}
+		if library.buildDylib() {
+			return dylibVariation
 		}
 	}
+	return incomingVariation
+}
 
-	if rlibVariant && library.isFFILibrary() {
-		// If an rlib variant is set and this is an FFI library, make it the
-		// default variant so CC can link against it appropriately.
-		mctx.AliasVariation(rlibVariation)
-	} else if emptyVariant {
-		// If there's an empty variant, alias it so it is the default variant
-		mctx.AliasVariation("")
+func (libraryTransitionMutator) Mutate(ctx android.BottomUpMutatorContext, variation string) {
+	m, ok := ctx.Module().(*Module)
+	if !ok || m.compiler == nil {
+		return
+	}
+	library, ok := m.compiler.(libraryInterface)
+	if !ok {
+		return
+	}
+
+	switch variation {
+	case rlibVariation:
+		library.setRlib()
+	case dylibVariation:
+		library.setDylib()
+		if m.ModuleBase.ImageVariation().Variation == android.VendorRamdiskVariation {
+			// TODO(b/165791368)
+			// Disable dylib Vendor Ramdisk variations until we support these.
+			m.Disable()
+		}
+
+	case sourceVariation:
+		library.setSource()
+		// The source variant does not produce any library.
+		// Disable the compilation steps.
+		m.compiler.SetDisabled()
 	}
 
 	// If a source variant is created, add an inter-variant dependency
 	// between the other variants and the source variant.
-	if sourceVariant {
-		sv := modules[0]
-		for _, v := range modules[1:] {
-			if !v.Enabled(mctx) {
-				continue
-			}
-			mctx.AddInterVariantDependency(sourceDepTag, v, sv)
-		}
-		// Alias the source variation so it can be named directly in "srcs" properties.
-		mctx.AliasVariation("source")
+	if m.sourceProvider != nil && variation != sourceVariation {
+		ctx.AddVariationDependencies(
+			[]blueprint.Variation{
+				{"rust_libraries", sourceVariation},
+			},
+			sourceDepTag, ctx.ModuleName())
 	}
 }
 
-func LibstdMutator(mctx android.BottomUpMutatorContext) {
-	if m, ok := mctx.Module().(*Module); ok && m.compiler != nil && !m.compiler.Disabled() {
-		switch library := m.compiler.(type) {
-		case libraryInterface:
-			// Only create a variant if a library is actually being built.
-			if library.rlib() && !library.sysroot() {
-				// If this is a rust_ffi variant it only needs rlib-std
-				if library.isFFILibrary() {
-					variants := []string{"rlib-std"}
-					modules := mctx.CreateLocalVariations(variants...)
-					rlib := modules[0].(*Module)
-					rlib.compiler.(libraryInterface).setRlibStd()
-					rlib.Properties.RustSubName += RlibStdlibSuffix
-					mctx.AliasVariation("rlib-std")
-				} else {
-					variants := []string{"rlib-std", "dylib-std"}
-					modules := mctx.CreateLocalVariations(variants...)
+type libstdTransitionMutator struct{}
 
-					rlib := modules[0].(*Module)
-					dylib := modules[1].(*Module)
-					rlib.compiler.(libraryInterface).setRlibStd()
-					dylib.compiler.(libraryInterface).setDylibStd()
-					if dylib.ModuleBase.ImageVariation().Variation == android.VendorRamdiskVariation {
-						// TODO(b/165791368)
-						// Disable rlibs that link against dylib-std on vendor ramdisk variations until those dylib
-						// variants are properly supported.
-						dylib.Disable()
-					}
-					rlib.Properties.RustSubName += RlibStdlibSuffix
+func (libstdTransitionMutator) Split(ctx android.BaseModuleContext) []string {
+	if m, ok := ctx.Module().(*Module); ok && m.compiler != nil && !m.compiler.Disabled() {
+		// Only create a variant if a library is actually being built.
+		if library, ok := m.compiler.(libraryInterface); ok {
+			if library.rlib() && !library.sysroot() {
+				if library.isFFILibrary() {
+					return []string{"rlib-std"}
+				} else {
+					return []string{"rlib-std", "dylib-std"}
 				}
 			}
 		}
 	}
+	return []string{""}
+}
+
+func (libstdTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
+	return ""
+}
+
+func (libstdTransitionMutator) IncomingTransition(ctx android.IncomingTransitionContext, incomingVariation string) string {
+	if m, ok := ctx.Module().(*Module); ok && m.compiler != nil && !m.compiler.Disabled() {
+		if library, ok := m.compiler.(libraryInterface); ok {
+			if library.shared() {
+				return ""
+			}
+			if library.rlib() && !library.sysroot() {
+				if incomingVariation != "" {
+					return incomingVariation
+				}
+				return "rlib-std"
+			}
+		}
+	}
+	return ""
+}
+
+func (libstdTransitionMutator) Mutate(ctx android.BottomUpMutatorContext, variation string) {
+	if variation == "rlib-std" {
+		rlib := ctx.Module().(*Module)
+		rlib.compiler.(libraryInterface).setRlibStd()
+		rlib.Properties.RustSubName += RlibStdlibSuffix
+	} else if variation == "dylib-std" {
+		dylib := ctx.Module().(*Module)
+		dylib.compiler.(libraryInterface).setDylibStd()
+		if dylib.ModuleBase.ImageVariation().Variation == android.VendorRamdiskVariation {
+			// TODO(b/165791368)
+			// Disable rlibs that link against dylib-std on vendor ramdisk variations until those dylib
+			// variants are properly supported.
+			dylib.Disable()
+		}
+	}
 }
diff --git a/rust/rust.go b/rust/rust.go
index 9dae75e..3402adc 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -37,20 +37,24 @@
 
 func init() {
 	android.RegisterModuleType("rust_defaults", defaultsFactory)
-	android.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.BottomUp("rust_libraries", LibraryMutator).Parallel()
-		ctx.BottomUp("rust_stdlinkage", LibstdMutator).Parallel()
-		ctx.BottomUp("rust_begin", BeginMutator).Parallel()
-	})
-	android.PostDepsMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.BottomUp("rust_sanitizers", rustSanitizerRuntimeMutator).Parallel()
-	})
+	android.PreDepsMutators(registerPreDepsMutators)
+	android.PostDepsMutators(registerPostDepsMutators)
 	pctx.Import("android/soong/android")
 	pctx.Import("android/soong/rust/config")
 	pctx.ImportAs("cc_config", "android/soong/cc/config")
 	android.InitRegistrationContext.RegisterParallelSingletonType("kythe_rust_extract", kytheExtractRustFactory)
 }
 
+func registerPreDepsMutators(ctx android.RegisterMutatorsContext) {
+	ctx.Transition("rust_libraries", &libraryTransitionMutator{})
+	ctx.Transition("rust_stdlinkage", &libstdTransitionMutator{})
+	ctx.BottomUp("rust_begin", BeginMutator).Parallel()
+}
+
+func registerPostDepsMutators(ctx android.RegisterMutatorsContext) {
+	ctx.BottomUp("rust_sanitizers", rustSanitizerRuntimeMutator).Parallel()
+}
+
 type Flags struct {
 	GlobalRustFlags []string // Flags that apply globally to rust
 	GlobalLinkFlags []string // Flags that apply globally to linker
@@ -1128,10 +1132,11 @@
 }
 
 var (
-	rlibVariation  = "rlib"
-	dylibVariation = "dylib"
-	rlibAutoDep    = autoDep{variation: rlibVariation, depTag: rlibDepTag}
-	dylibAutoDep   = autoDep{variation: dylibVariation, depTag: dylibDepTag}
+	sourceVariation = "source"
+	rlibVariation   = "rlib"
+	dylibVariation  = "dylib"
+	rlibAutoDep     = autoDep{variation: rlibVariation, depTag: rlibDepTag}
+	dylibAutoDep    = autoDep{variation: dylibVariation, depTag: dylibDepTag}
 )
 
 type autoDeppable interface {
@@ -1613,7 +1618,6 @@
 	}
 
 	rlibDepVariations := commonDepVariations
-	rlibDepVariations = append(rlibDepVariations, blueprint.Variation{Mutator: "link", Variation: ""})
 
 	if lib, ok := mod.compiler.(libraryInterface); !ok || !lib.sysroot() {
 		rlibDepVariations = append(rlibDepVariations,
@@ -1629,7 +1633,6 @@
 
 	// dylibs
 	dylibDepVariations := append(commonDepVariations, blueprint.Variation{Mutator: "rust_libraries", Variation: dylibVariation})
-	dylibDepVariations = append(dylibDepVariations, blueprint.Variation{Mutator: "link", Variation: ""})
 
 	for _, lib := range deps.Dylibs {
 		actx.AddVariationDependencies(dylibDepVariations, dylibDepTag, lib)
@@ -1650,7 +1653,6 @@
 					// otherwise select the rlib variant.
 					autoDepVariations := append(commonDepVariations,
 						blueprint.Variation{Mutator: "rust_libraries", Variation: autoDep.variation})
-					autoDepVariations = append(autoDepVariations, blueprint.Variation{Mutator: "link", Variation: ""})
 					if actx.OtherModuleDependencyVariantExists(autoDepVariations, lib) {
 						actx.AddVariationDependencies(autoDepVariations, autoDep.depTag, lib)
 
@@ -1664,8 +1666,7 @@
 		} else if _, ok := mod.sourceProvider.(*protobufDecorator); ok {
 			for _, lib := range deps.Rustlibs {
 				srcProviderVariations := append(commonDepVariations,
-					blueprint.Variation{Mutator: "rust_libraries", Variation: "source"})
-				srcProviderVariations = append(srcProviderVariations, blueprint.Variation{Mutator: "link", Variation: ""})
+					blueprint.Variation{Mutator: "rust_libraries", Variation: sourceVariation})
 
 				// Only add rustlib dependencies if they're source providers themselves.
 				// This is used to track which crate names need to be added to the source generated
@@ -1681,7 +1682,7 @@
 	if deps.Stdlibs != nil {
 		if mod.compiler.stdLinkage(ctx) == RlibLinkage {
 			for _, lib := range deps.Stdlibs {
-				actx.AddVariationDependencies(append(commonDepVariations, []blueprint.Variation{{Mutator: "rust_libraries", Variation: "rlib"}, {Mutator: "link", Variation: ""}}...),
+				actx.AddVariationDependencies(append(commonDepVariations, []blueprint.Variation{{Mutator: "rust_libraries", Variation: "rlib"}}...),
 					rlibDepTag, lib)
 			}
 		} else {
diff --git a/rust/rust_test.go b/rust/rust_test.go
index 0d005d0..eeedf3f 100644
--- a/rust/rust_test.go
+++ b/rust/rust_test.go
@@ -60,6 +60,7 @@
 // testRust returns a TestContext in which a basic environment has been setup.
 // This environment contains a few mocked files. See rustMockedFiles for the list of these files.
 func testRust(t *testing.T, bp string) *android.TestContext {
+	t.Helper()
 	skipTestIfOsNotSupported(t)
 	result := android.GroupFixturePreparers(
 		prepareForRustTest,
diff --git a/rust/test.go b/rust/test.go
index 3087d8d..b7ddd06 100644
--- a/rust/test.go
+++ b/rust/test.go
@@ -116,7 +116,8 @@
 }
 
 func (test *testDecorator) install(ctx ModuleContext) {
-	testInstallBase := "/data/local/tests/unrestricted"
+	// TODO: (b/167308193) Switch to /data/local/tests/unrestricted as the default install base.
+	testInstallBase := "/data/local/tmp"
 	if ctx.RustModule().InVendorOrProduct() {
 		testInstallBase = "/data/local/tests/vendor"
 	}
diff --git a/rust/testing.go b/rust/testing.go
index 6ee49a9..32cc823 100644
--- a/rust/testing.go
+++ b/rust/testing.go
@@ -200,15 +200,8 @@
 	ctx.RegisterModuleType("rust_prebuilt_library", PrebuiltLibraryFactory)
 	ctx.RegisterModuleType("rust_prebuilt_dylib", PrebuiltDylibFactory)
 	ctx.RegisterModuleType("rust_prebuilt_rlib", PrebuiltRlibFactory)
-	ctx.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
-		// rust mutators
-		ctx.BottomUp("rust_libraries", LibraryMutator).Parallel()
-		ctx.BottomUp("rust_stdlinkage", LibstdMutator).Parallel()
-		ctx.BottomUp("rust_begin", BeginMutator).Parallel()
-	})
+	ctx.PreDepsMutators(registerPreDepsMutators)
 	ctx.RegisterParallelSingletonType("rust_project_generator", rustProjectGeneratorSingleton)
 	ctx.RegisterParallelSingletonType("kythe_rust_extract", kytheExtractRustFactory)
-	ctx.PostDepsMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.BottomUp("rust_sanitizers", rustSanitizerRuntimeMutator).Parallel()
-	})
+	ctx.PostDepsMutators(registerPostDepsMutators)
 }
diff --git a/scripts/run-ckati.sh b/scripts/run-ckati.sh
index b670c8a..70f5a7a 100755
--- a/scripts/run-ckati.sh
+++ b/scripts/run-ckati.sh
@@ -73,12 +73,12 @@
   --writable out/ \
   -f build/make/core/main.mk \
   "${tracing[@]}" \
-  ANDROID_JAVA_HOME=prebuilts/jdk/jdk17/linux-x86 \
+  ANDROID_JAVA_HOME=prebuilts/jdk/jdk21/linux-x86 \
   ASAN_SYMBOLIZER_PATH=$PWD/prebuilts/clang/host/linux-x86/llvm-binutils-stable/llvm-symbolizer \
   BUILD_DATETIME_FILE="$timestamp_file" \
   BUILD_HOSTNAME=$(hostname) \
   BUILD_USERNAME="$USER" \
-  JAVA_HOME=$PWD/prebuilts/jdk/jdk17/linux-x86 \
+  JAVA_HOME=$PWD/prebuilts/jdk/jdk21/linux-x86 \
   KATI_PACKAGE_MK_DIR="{$out}/target/product/${target_device}/CONFIG/kati_packaging" \
   OUT_DIR="$out" \
   PATH="$PWD/prebuilts/build-tools/path/linux-x86:$PWD/${out}/.path" \
diff --git a/ui/build/Android.bp b/ui/build/Android.bp
index ee286f6..fcf29c5 100644
--- a/ui/build/Android.bp
+++ b/ui/build/Android.bp
@@ -36,6 +36,7 @@
         "blueprint-bootstrap",
         "blueprint-microfactory",
         "soong-android",
+        "soong-elf",
         "soong-finder",
         "soong-remoteexec",
         "soong-shared",
diff --git a/ui/build/build.go b/ui/build/build.go
index 03d8392..c7319ed 100644
--- a/ui/build/build.go
+++ b/ui/build/build.go
@@ -22,6 +22,7 @@
 	"sync"
 	"text/template"
 
+	"android/soong/elf"
 	"android/soong/ui/metrics"
 )
 
@@ -344,6 +345,7 @@
 			installCleanIfNecessary(ctx, config)
 		}
 		runNinjaForBuild(ctx, config)
+		updateBuildIdDir(ctx, config)
 	}
 
 	if what&RunDistActions != 0 {
@@ -351,6 +353,16 @@
 	}
 }
 
+func updateBuildIdDir(ctx Context, config Config) {
+	ctx.BeginTrace(metrics.RunShutdownTool, "update_build_id_dir")
+	defer ctx.EndTrace()
+
+	symbolsDir := filepath.Join(config.ProductOut(), "symbols")
+	if err := elf.UpdateBuildIdDir(symbolsDir); err != nil {
+		ctx.Printf("failed to update %s/.build-id: %v", symbolsDir, err)
+	}
+}
+
 func evaluateWhatToRun(config Config, verboseln func(v ...interface{})) int {
 	//evaluate what to run
 	what := 0
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index 81c678d..6c9a1eb 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -86,28 +86,28 @@
 // This list specifies whether a particular binary from $PATH is allowed to be
 // run during the build. For more documentation, see path_interposer.go .
 var Configuration = map[string]PathConfig{
-	"bash":           Allowed,
-	"diff":           Allowed,
-	"dlv":            Allowed,
-	"expr":           Allowed,
-	"fuser":          Allowed,
-	"gcert":          Allowed,
-	"gcertstatus":    Allowed,
-	"gcloud":         Allowed,
-	"git":            Allowed,
-	"hexdump":        Allowed,
-	"jar":            Allowed,
-	"java":           Allowed,
-	"javap":          Allowed,
-	"lsof":           Allowed,
-	"openssl":        Allowed,
-	"pstree":         Allowed,
-	"rsync":          Allowed,
-	"sh":             Allowed,
-	"stubby":         Allowed,
-	"tr":             Allowed,
-	"unzip":          Allowed,
-	"zip":            Allowed,
+	"bash":        Allowed,
+	"diff":        Allowed,
+	"dlv":         Allowed,
+	"expr":        Allowed,
+	"fuser":       Allowed,
+	"gcert":       Allowed,
+	"gcertstatus": Allowed,
+	"gcloud":      Allowed,
+	"git":         Allowed,
+	"hexdump":     Allowed,
+	"jar":         Allowed,
+	"java":        Allowed,
+	"javap":       Allowed,
+	"lsof":        Allowed,
+	"openssl":     Allowed,
+	"pstree":      Allowed,
+	"rsync":       Allowed,
+	"sh":          Allowed,
+	"stubby":      Allowed,
+	"tr":          Allowed,
+	"unzip":       Allowed,
+	"zip":         Allowed,
 
 	// Host toolchain is removed. In-tree toolchain should be used instead.
 	// GCC also can't find cc1 with this implementation.
diff --git a/ui/terminal/format.go b/ui/terminal/format.go
index 241a1dd..01f8b0d 100644
--- a/ui/terminal/format.go
+++ b/ui/terminal/format.go
@@ -23,26 +23,28 @@
 )
 
 type formatter struct {
-	format string
-	quiet  bool
-	start  time.Time
+	colorize bool
+	format   string
+	quiet    bool
+	start    time.Time
 }
 
 // newFormatter returns a formatter for formatting output to
 // the terminal in a format similar to Ninja.
 // format takes nearly all the same options as NINJA_STATUS.
 // %c is currently unsupported.
-func newFormatter(format string, quiet bool) formatter {
+func newFormatter(colorize bool, format string, quiet bool) formatter {
 	return formatter{
-		format: format,
-		quiet:  quiet,
-		start:  time.Now(),
+		colorize: colorize,
+		format:   format,
+		quiet:    quiet,
+		start:    time.Now(),
 	}
 }
 
 func (s formatter) message(level status.MsgLevel, message string) string {
 	if level >= status.ErrorLvl {
-		return fmt.Sprintf("FAILED: %s", message)
+		return fmt.Sprintf("%s %s", s.failedString(), message)
 	} else if level > status.StatusLvl {
 		return fmt.Sprintf("%s%s", level.Prefix(), message)
 	} else if level == status.StatusLvl {
@@ -127,9 +129,9 @@
 	if result.Error != nil {
 		targets := strings.Join(result.Outputs, " ")
 		if s.quiet || result.Command == "" {
-			ret = fmt.Sprintf("FAILED: %s\n%s", targets, result.Output)
+			ret = fmt.Sprintf("%s %s\n%s", s.failedString(), targets, result.Output)
 		} else {
-			ret = fmt.Sprintf("FAILED: %s\n%s\n%s", targets, result.Command, result.Output)
+			ret = fmt.Sprintf("%s %s\n%s\n%s", s.failedString(), targets, result.Command, result.Output)
 		}
 	} else if result.Output != "" {
 		ret = result.Output
@@ -141,3 +143,11 @@
 
 	return ret
 }
+
+func (s formatter) failedString() string {
+	failed := "FAILED:"
+	if s.colorize {
+		failed = ansi.red() + ansi.bold() + failed + ansi.regular()
+	}
+	return failed
+}
diff --git a/ui/terminal/status.go b/ui/terminal/status.go
index 2ad174f..92f2994 100644
--- a/ui/terminal/status.go
+++ b/ui/terminal/status.go
@@ -27,9 +27,10 @@
 // statusFormat takes nearly all the same options as NINJA_STATUS.
 // %c is currently unsupported.
 func NewStatusOutput(w io.Writer, statusFormat string, forceSimpleOutput, quietBuild, forceKeepANSI bool) status.StatusOutput {
-	formatter := newFormatter(statusFormat, quietBuild)
+	canUseSmartFormatting := !forceSimpleOutput && isSmartTerminal(w)
+	formatter := newFormatter(canUseSmartFormatting, statusFormat, quietBuild)
 
-	if !forceSimpleOutput && isSmartTerminal(w) {
+	if canUseSmartFormatting {
 		return NewSmartStatusOutput(w, formatter)
 	} else {
 		return NewSimpleStatusOutput(w, formatter, forceKeepANSI)
diff --git a/ui/terminal/status_test.go b/ui/terminal/status_test.go
index 8dd1809..991eca0 100644
--- a/ui/terminal/status_test.go
+++ b/ui/terminal/status_test.go
@@ -58,7 +58,7 @@
 		{
 			name:   "action with error",
 			calls:  actionsWithError,
-			smart:  "\r\x1b[1m[  0% 0/3] action1\x1b[0m\x1b[K\r\x1b[1m[ 33% 1/3] action1\x1b[0m\x1b[K\r\x1b[1m[ 33% 1/3] action2\x1b[0m\x1b[K\r\x1b[1m[ 66% 2/3] action2\x1b[0m\x1b[K\nFAILED: f1 f2\ntouch f1 f2\nerror1\nerror2\n\r\x1b[1m[ 66% 2/3] action3\x1b[0m\x1b[K\r\x1b[1m[100% 3/3] action3\x1b[0m\x1b[K\n",
+			smart:  "\r\x1b[1m[  0% 0/3] action1\x1b[0m\x1b[K\r\x1b[1m[ 33% 1/3] action1\x1b[0m\x1b[K\r\x1b[1m[ 33% 1/3] action2\x1b[0m\x1b[K\r\x1b[1m[ 66% 2/3] action2\x1b[0m\x1b[K\n\x1b[31m\x1b[1mFAILED:\x1b[0m f1 f2\ntouch f1 f2\nerror1\nerror2\n\r\x1b[1m[ 66% 2/3] action3\x1b[0m\x1b[K\r\x1b[1m[100% 3/3] action3\x1b[0m\x1b[K\n",
 			simple: "[ 33% 1/3] action1\n[ 66% 2/3] action2\nFAILED: f1 f2\ntouch f1 f2\nerror1\nerror2\n[100% 3/3] action3\n",
 		},
 		{
@@ -70,7 +70,7 @@
 		{
 			name:   "messages",
 			calls:  actionsWithMessages,
-			smart:  "\r\x1b[1m[  0% 0/2] action1\x1b[0m\x1b[K\r\x1b[1m[ 50% 1/2] action1\x1b[0m\x1b[K\r\x1b[1mstatus\x1b[0m\x1b[K\r\x1b[Kprint\nFAILED: error\n\r\x1b[1m[ 50% 1/2] action2\x1b[0m\x1b[K\r\x1b[1m[100% 2/2] action2\x1b[0m\x1b[K\n",
+			smart:  "\r\x1b[1m[  0% 0/2] action1\x1b[0m\x1b[K\r\x1b[1m[ 50% 1/2] action1\x1b[0m\x1b[K\r\x1b[1mstatus\x1b[0m\x1b[K\r\x1b[Kprint\n\x1b[31m\x1b[1mFAILED:\x1b[0m error\n\r\x1b[1m[ 50% 1/2] action2\x1b[0m\x1b[K\r\x1b[1m[100% 2/2] action2\x1b[0m\x1b[K\n",
 			simple: "[ 50% 1/2] action1\nstatus\nprint\nFAILED: error\n[100% 2/2] action2\n",
 		},
 		{
@@ -362,7 +362,7 @@
 
 	stat.Flush()
 
-	w := "\r\x1b[1m[  0% 0/2] action1\x1b[0m\x1b[K\r\x1b[1m[  0% 0/2] action2\x1b[0m\x1b[K\r\x1b[1m[ 50% 1/2] action1\x1b[0m\x1b[K\nFAILED: \nOutput1\n\r\x1b[1m[100% 2/2] action2\x1b[0m\x1b[K\nThere was 1 action that completed after the action that failed. See verbose.log.gz for its output.\n"
+	w := "\r\x1b[1m[  0% 0/2] action1\x1b[0m\x1b[K\r\x1b[1m[  0% 0/2] action2\x1b[0m\x1b[K\r\x1b[1m[ 50% 1/2] action1\x1b[0m\x1b[K\n\x1b[31m\x1b[1mFAILED:\x1b[0m \nOutput1\n\r\x1b[1m[100% 2/2] action2\x1b[0m\x1b[K\nThere was 1 action that completed after the action that failed. See verbose.log.gz for its output.\n"
 
 	if g := smart.String(); g != w {
 		t.Errorf("want:\n%q\ngot:\n%q", w, g)
@@ -407,7 +407,7 @@
 
 	stat.Flush()
 
-	w := "\r\x1b[1m[  0% 0/2] action1\x1b[0m\x1b[K\r\x1b[1m[  0% 0/2] action2\x1b[0m\x1b[K\r\x1b[1m[  0% 0/2] action3\x1b[0m\x1b[K\r\x1b[1m[ 50% 1/2] action1\x1b[0m\x1b[K\nFAILED: \nOutput1\n\r\x1b[1m[100% 2/2] action2\x1b[0m\x1b[K\r\x1b[1m[150% 3/2] action3\x1b[0m\x1b[K\nThere were 2 actions that completed after the action that failed. See verbose.log.gz for their output.\n"
+	w := "\r\x1b[1m[  0% 0/2] action1\x1b[0m\x1b[K\r\x1b[1m[  0% 0/2] action2\x1b[0m\x1b[K\r\x1b[1m[  0% 0/2] action3\x1b[0m\x1b[K\r\x1b[1m[ 50% 1/2] action1\x1b[0m\x1b[K\n\x1b[31m\x1b[1mFAILED:\x1b[0m \nOutput1\n\r\x1b[1m[100% 2/2] action2\x1b[0m\x1b[K\r\x1b[1m[150% 3/2] action3\x1b[0m\x1b[K\nThere were 2 actions that completed after the action that failed. See verbose.log.gz for their output.\n"
 
 	if g := smart.String(); g != w {
 		t.Errorf("want:\n%q\ngot:\n%q", w, g)
@@ -445,7 +445,7 @@
 
 	stat.Flush()
 
-	w := "\r\x1b[1m[  0% 0/2] action1\x1b[0m\x1b[K\r\x1b[1m[  0% 0/2] action2\x1b[0m\x1b[K\r\x1b[1m[ 50% 1/2] action1\x1b[0m\x1b[K\nFAILED: \nOutput1\n\r\x1b[1m[100% 2/2] action2\x1b[0m\x1b[K\nFAILED: \nOutput2\n"
+	w := "\r\x1b[1m[  0% 0/2] action1\x1b[0m\x1b[K\r\x1b[1m[  0% 0/2] action2\x1b[0m\x1b[K\r\x1b[1m[ 50% 1/2] action1\x1b[0m\x1b[K\n\x1b[31m\x1b[1mFAILED:\x1b[0m \nOutput1\n\r\x1b[1m[100% 2/2] action2\x1b[0m\x1b[K\n\x1b[31m\x1b[1mFAILED:\x1b[0m \nOutput2\n"
 
 	if g := smart.String(); g != w {
 		t.Errorf("want:\n%q\ngot:\n%q", w, g)