diff --git a/android/allowlists/allowlists.go b/android/allowlists/allowlists.go
index 5c120e2..ccfad00 100644
--- a/android/allowlists/allowlists.go
+++ b/android/allowlists/allowlists.go
@@ -226,12 +226,14 @@
 		"build/bazel/ci/dist":/* recursive = */ false,
 		"build/bazel/examples/android_app":/* recursive = */ true,
 		"build/bazel/examples/java":/* recursive = */ true,
+		"build/bazel/examples/partitions":/* recursive = */ true,
 		"build/bazel/bazel_skylib":/* recursive = */ true,
 		"build/bazel/rules":/* recursive = */ true,
 		"build/bazel/rules_cc":/* recursive = */ true,
 		"build/bazel/scripts":/* recursive = */ true,
 		"build/bazel/tests":/* recursive = */ true,
 		"build/bazel/platforms":/* recursive = */ true,
+		"build/bazel/product_config":/* recursive = */ true,
 		"build/bazel/product_variables":/* recursive = */ true,
 		"build/bazel/vendor/google":/* recursive = */ true,
 		"build/bazel_common_rules":/* recursive = */ true,
diff --git a/android/bazel_handler.go b/android/bazel_handler.go
index 33b67ab..27255d1 100644
--- a/android/bazel_handler.go
+++ b/android/bazel_handler.go
@@ -21,6 +21,7 @@
 	"io/ioutil"
 	"os"
 	"os/exec"
+	"path"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -528,7 +529,7 @@
 	configNodesSection := ""
 
 	labelsByConfig := map[string][]string{}
-	for val, _ := range context.requests {
+	for val := range context.requests {
 		labelString := fmt.Sprintf("\"@%s\"", val.label)
 		configString := getConfigString(val)
 		labelsByConfig[configString] = append(labelsByConfig[configString], labelString)
@@ -566,7 +567,7 @@
 // request type.
 func (context *bazelContext) cqueryStarlarkFileContents() []byte {
 	requestTypeToCqueryIdEntries := map[cqueryRequest][]string{}
-	for val, _ := range context.requests {
+	for val := range context.requests {
 		cqueryId := getCqueryId(val)
 		mapEntryString := fmt.Sprintf("%q : True", cqueryId)
 		requestTypeToCqueryIdEntries[val.requestType] =
@@ -870,53 +871,14 @@
 		})
 	}
 
-	// Register bazel-owned build statements (obtained from the aquery invocation).
+	executionRoot := path.Join(ctx.Config().BazelContext.OutputBase(), "execroot", "__main__")
+	bazelOutDir := path.Join(executionRoot, "bazel-out")
 	for index, buildStatement := range ctx.Config().BazelContext.BuildStatementsToRegister() {
 		if len(buildStatement.Command) < 1 {
 			panic(fmt.Sprintf("unhandled build statement: %v", buildStatement))
 		}
 		rule := NewRuleBuilder(pctx, ctx)
-		cmd := rule.Command()
-
-		// cd into Bazel's execution root, which is the action cwd.
-		cmd.Text(fmt.Sprintf("cd %s/execroot/__main__ &&", ctx.Config().BazelContext.OutputBase()))
-
-		// Remove old outputs, as some actions might not rerun if the outputs are detected.
-		if len(buildStatement.OutputPaths) > 0 {
-			cmd.Text("rm -f")
-			for _, outputPath := range buildStatement.OutputPaths {
-				cmd.Text(outputPath)
-			}
-			cmd.Text("&&")
-		}
-
-		for _, pair := range buildStatement.Env {
-			// Set per-action env variables, if any.
-			cmd.Flag(pair.Key + "=" + pair.Value)
-		}
-
-		// The actual Bazel action.
-		cmd.Text(buildStatement.Command)
-
-		for _, outputPath := range buildStatement.OutputPaths {
-			cmd.ImplicitOutput(PathForBazelOut(ctx, outputPath))
-		}
-		for _, inputPath := range buildStatement.InputPaths {
-			cmd.Implicit(PathForBazelOut(ctx, inputPath))
-		}
-		for _, inputDepsetHash := range buildStatement.InputDepsetHashes {
-			otherDepsetName := bazelDepsetName(inputDepsetHash)
-			cmd.Implicit(PathForPhony(ctx, otherDepsetName))
-		}
-
-		if depfile := buildStatement.Depfile; depfile != nil {
-			cmd.ImplicitDepFile(PathForBazelOut(ctx, *depfile))
-		}
-
-		for _, symlinkPath := range buildStatement.SymlinkPaths {
-			cmd.ImplicitSymlinkOutput(PathForBazelOut(ctx, symlinkPath))
-		}
-
+		createCommand(rule.Command(), buildStatement, executionRoot, bazelOutDir, ctx)
 		// This is required to silence warnings pertaining to unexpected timestamps. Particularly,
 		// some Bazel builtins (such as files in the bazel_tools directory) have far-future
 		// timestamps. Without restat, Ninja would emit warnings that the input files of a
@@ -928,6 +890,58 @@
 	}
 }
 
+// Register bazel-owned build statements (obtained from the aquery invocation).
+func createCommand(cmd *RuleBuilderCommand, buildStatement bazel.BuildStatement, executionRoot string, bazelOutDir string, ctx PathContext) {
+	// executionRoot is the action cwd.
+	cmd.Text(fmt.Sprintf("cd '%s' &&", executionRoot))
+
+	// Remove old outputs, as some actions might not rerun if the outputs are detected.
+	if len(buildStatement.OutputPaths) > 0 {
+		cmd.Text("rm -f")
+		for _, outputPath := range buildStatement.OutputPaths {
+			cmd.Text(outputPath)
+		}
+		cmd.Text("&&")
+	}
+
+	for _, pair := range buildStatement.Env {
+		// Set per-action env variables, if any.
+		cmd.Flag(pair.Key + "=" + pair.Value)
+	}
+
+	// The actual Bazel action.
+	cmd.Text(buildStatement.Command)
+
+	for _, outputPath := range buildStatement.OutputPaths {
+		cmd.ImplicitOutput(PathForBazelOut(ctx, outputPath))
+	}
+	for _, inputPath := range buildStatement.InputPaths {
+		cmd.Implicit(PathForBazelOut(ctx, inputPath))
+	}
+	for _, inputDepsetHash := range buildStatement.InputDepsetHashes {
+		otherDepsetName := bazelDepsetName(inputDepsetHash)
+		cmd.Implicit(PathForPhony(ctx, otherDepsetName))
+	}
+
+	if depfile := buildStatement.Depfile; depfile != nil {
+		// The paths in depfile are relative to `executionRoot`.
+		// Hence, they need to be corrected by replacing "bazel-out"
+		// with the full `bazelOutDir`.
+		// Otherwise, implicit outputs and implicit inputs under "bazel-out/"
+		// would be deemed missing.
+		// (Note: The regexp uses a capture group because the version of sed
+		//  does not support a look-behind pattern.)
+		replacement := fmt.Sprintf(`&& sed -i'' -E 's@(^|\s|")bazel-out/@\1%s/@g' '%s'`,
+			bazelOutDir, *depfile)
+		cmd.Text(replacement)
+		cmd.ImplicitDepFile(PathForBazelOut(ctx, *depfile))
+	}
+
+	for _, symlinkPath := range buildStatement.SymlinkPaths {
+		cmd.ImplicitSymlinkOutput(PathForBazelOut(ctx, symlinkPath))
+	}
+}
+
 func getCqueryId(key cqueryKey) string {
 	return key.label + "|" + getConfigString(key)
 }
diff --git a/android/bazel_handler_test.go b/android/bazel_handler_test.go
index dd9a7ed..935ce4e 100644
--- a/android/bazel_handler_test.go
+++ b/android/bazel_handler_test.go
@@ -57,8 +57,13 @@
 }
 
 func TestInvokeBazelPopulatesBuildStatements(t *testing.T) {
-	bazelContext, _ := testBazelContext(t, map[bazelCommand]string{
-		bazelCommand{command: "aquery", expression: "deps(@soong_injection//mixed_builds:buildroot)"}: `
+	type testCase struct {
+		input   string
+		command string
+	}
+
+	var testCases = []testCase{
+		{`
 {
   "artifacts": [{
     "id": 1,
@@ -88,15 +93,60 @@
     "label": "two"
   }]
 }`,
-	})
-	err := bazelContext.InvokeBazel(testConfig)
-	if err != nil {
-		t.Fatalf("Did not expect error invoking Bazel, but got %s", err)
+			"cd 'er' && rm -f one && touch foo",
+		}, {`
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 10
+  }, {
+    "id": 2,
+    "pathFragmentId": 20
+  }],
+  "actions": [{
+    "targetId": 100,
+    "actionKey": "x",
+    "mnemonic": "x",
+    "arguments": ["bogus", "command"],
+    "outputIds": [1, 2],
+    "primaryOutputId": 1
+  }],
+  "pathFragments": [{
+    "id": 10,
+    "label": "one",
+    "parentId": 30
+  }, {
+    "id": 20,
+    "label": "one.d",
+    "parentId": 30
+  }, {
+    "id": 30,
+    "label": "parent"
+  }]
+}`,
+			`cd 'er' && rm -f parent/one && bogus command && sed -i'' -E 's@(^|\s|")bazel-out/@\1bo/@g' 'parent/one.d'`,
+		},
 	}
 
-	got := bazelContext.BuildStatementsToRegister()
-	if want := 1; len(got) != want {
-		t.Errorf("Expected %d registered build statements, got %#v", want, got)
+	for _, testCase := range testCases {
+		bazelContext, _ := testBazelContext(t, map[bazelCommand]string{
+			bazelCommand{command: "aquery", expression: "deps(@soong_injection//mixed_builds:buildroot)"}: testCase.input})
+
+		err := bazelContext.InvokeBazel(testConfig)
+		if err != nil {
+			t.Fatalf("Did not expect error invoking Bazel, but got %s", err)
+		}
+
+		got := bazelContext.BuildStatementsToRegister()
+		if want := 1; len(got) != want {
+			t.Errorf("expected %d registered build statements, but got %#v", want, got)
+		}
+
+		cmd := RuleBuilderCommand{}
+		createCommand(&cmd, got[0], "er", "bo", PathContextForTesting(TestConfig("out", nil, "", nil)))
+		if actual := cmd.buf.String(); testCase.command != actual {
+			t.Errorf("expected: [%s], actual: [%s]", testCase.command, actual)
+		}
 	}
 }
 
diff --git a/android/mutator.go b/android/mutator.go
index 7f93baf..9e4aa59 100644
--- a/android/mutator.go
+++ b/android/mutator.go
@@ -440,6 +440,64 @@
 	// reached
 	DepTag() blueprint.DependencyTag
 }
+
+// Transition mutators implement a top-down mechanism where a module tells its
+// direct dependencies what variation they should be built in but the dependency
+// has the final say.
+//
+// When implementing a transition mutator, one needs to implement four methods:
+//   - Split() that tells what variations a module has by itself
+//   - OutgoingTransition() where a module tells what it wants from its
+//     dependency
+//   - IncomingTransition() where a module has the final say about its own
+//     variation
+//   - Mutate() that changes the state of a module depending on its variation
+//
+// That the effective variation of module B when depended on by module A is the
+// composition the outgoing transition of module A and the incoming transition
+// of module B.
+//
+// the outgoing transition should not take the properties of the dependency into
+// account, only those of the module that depends on it. For this reason, the
+// dependency is not even passed into it as an argument. Likewise, the incoming
+// transition should not take the properties of the depending module into
+// account and is thus not informed about it. This makes for a nice
+// decomposition of the decision logic.
+//
+// A given transition mutator only affects its own variation; other variations
+// stay unchanged along the dependency edges.
+//
+// Soong makes sure that all modules are created in the desired variations and
+// that dependency edges are set up correctly. This ensures that "missing
+// variation" errors do not happen and allows for more flexible changes in the
+// value of the variation among dependency edges (as oppposed to bottom-up
+// mutators where if module A in variation X depends on module B and module B
+// has that variation X, A must depend on variation X of B)
+//
+// The limited power of the context objects passed to individual mutators
+// methods also makes it more difficult to shoot oneself in the foot. Complete
+// safety is not guaranteed because no one prevents individual transition
+// mutators from mutating modules in illegal ways and for e.g. Split() or
+// Mutate() to run their own visitations of the transitive dependency of the
+// module and both of these are bad ideas, but it's better than no guardrails at
+// all.
+//
+// This model is pretty close to Bazel's configuration transitions. The mapping
+// between concepts in Soong and Bazel is as follows:
+//   - Module == configured target
+//   - Variant == configuration
+//   - Variation name == configuration flag
+//   - Variation == configuration flag value
+//   - Outgoing transition == attribute transition
+//   - Incoming transition == rule transition
+//
+// The Split() method does not have a Bazel equivalent and Bazel split
+// transitions do not have a Soong equivalent.
+//
+// Mutate() does not make sense in Bazel due to the different models of the
+// two systems: when creating new variations, Soong clones the old module and
+// thus some way is needed to change it state whereas Bazel creates each
+// configuration of a given configured target anew.
 type TransitionMutator interface {
 	// Split returns the set of variations that should be created for a module no
 	// matter who depends on it. Used when Make depends on a particular variation
@@ -448,7 +506,7 @@
 	// called on.
 	Split(ctx BaseModuleContext) []string
 
-	// OutCalled on a module to determine which variation it wants from its direct
+	// Called on a module to determine which variation it wants from its direct
 	// dependencies. The dependency itself can override this decision. This method
 	// should not mutate the module itself.
 	OutgoingTransition(ctx OutgoingTransitionContext, sourceVariation string) string
diff --git a/bazel/aquery_test.go b/bazel/aquery_test.go
index 8ba8b5a..1da6340 100644
--- a/bazel/aquery_test.go
+++ b/bazel/aquery_test.go
@@ -17,6 +17,7 @@
 import (
 	"fmt"
 	"reflect"
+	"sort"
 	"testing"
 )
 
@@ -1484,50 +1485,54 @@
 			len(expected), len(actual), expected, actual)
 		return
 	}
-ACTUAL_LOOP:
-	for _, actualStatement := range actual {
-		for _, expectedStatement := range expected {
-			if buildStatementEquals(actualStatement, expectedStatement) {
-				continue ACTUAL_LOOP
-			}
+	type compareFn = func(i int, j int) bool
+	byCommand := func(slice []BuildStatement) compareFn {
+		return func(i int, j int) bool {
+			return slice[i].Command < slice[j].Command
 		}
-		t.Errorf("unexpected build statement %#v.\n expected: %#v",
-			actualStatement, expected)
-		return
+	}
+	sort.SliceStable(expected, byCommand(expected))
+	sort.SliceStable(actual, byCommand(actual))
+	for i, actualStatement := range actual {
+		expectedStatement := expected[i]
+		if differingField := buildStatementEquals(actualStatement, expectedStatement); differingField != "" {
+			t.Errorf("%s differs\nunexpected build statement %#v.\nexpected: %#v",
+				differingField, actualStatement, expected)
+			return
+		}
 	}
 }
 
-func buildStatementEquals(first BuildStatement, second BuildStatement) bool {
+func buildStatementEquals(first BuildStatement, second BuildStatement) string {
 	if first.Mnemonic != second.Mnemonic {
-		return false
+		return "Mnemonic"
 	}
 	if first.Command != second.Command {
-		return false
+		return "Command"
 	}
 	// Ordering is significant for environment variables.
 	if !reflect.DeepEqual(first.Env, second.Env) {
-		return false
+		return "Env"
 	}
 	// Ordering is irrelevant for input and output paths, so compare sets.
-	if !reflect.DeepEqual(stringSet(first.InputPaths), stringSet(second.InputPaths)) {
-		return false
+	if !reflect.DeepEqual(sortedStrings(first.InputPaths), sortedStrings(second.InputPaths)) {
+		return "InputPaths"
 	}
-	if !reflect.DeepEqual(stringSet(first.OutputPaths), stringSet(second.OutputPaths)) {
-		return false
+	if !reflect.DeepEqual(sortedStrings(first.OutputPaths), sortedStrings(second.OutputPaths)) {
+		return "OutputPaths"
 	}
-	if !reflect.DeepEqual(stringSet(first.SymlinkPaths), stringSet(second.SymlinkPaths)) {
-		return false
+	if !reflect.DeepEqual(sortedStrings(first.SymlinkPaths), sortedStrings(second.SymlinkPaths)) {
+		return "SymlinkPaths"
 	}
 	if first.Depfile != second.Depfile {
-		return false
+		return "Depfile"
 	}
-	return true
+	return ""
 }
 
-func stringSet(stringSlice []string) map[string]struct{} {
-	stringMap := make(map[string]struct{})
-	for _, s := range stringSlice {
-		stringMap[s] = struct{}{}
-	}
-	return stringMap
+func sortedStrings(stringSlice []string) []string {
+	sorted := make([]string, len(stringSlice))
+	copy(sorted, stringSlice)
+	sort.Strings(sorted)
+	return sorted
 }
diff --git a/cc/library.go b/cc/library.go
index 0fa01d7..c445a42 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -925,7 +925,6 @@
 		if ctx.Darwin() {
 			f = append(f,
 				"-dynamiclib",
-				"-single_module",
 				"-install_name @rpath/"+libName+flags.Toolchain.ShlibSuffix(),
 			)
 			if ctx.Arch().ArchType == android.X86 {
diff --git a/cc/linker.go b/cc/linker.go
index 78d2d41..76a60ca 100644
--- a/cc/linker.go
+++ b/cc/linker.go
@@ -436,11 +436,6 @@
 }
 
 func (linker *baseLinker) useClangLld(ctx ModuleContext) bool {
-	// Clang lld is not ready for for Darwin host executables yet.
-	// See https://lld.llvm.org/AtomLLD.html for status of lld for Mach-O.
-	if ctx.Darwin() {
-		return false
-	}
 	if linker.Properties.Use_clang_lld != nil {
 		return Bool(linker.Properties.Use_clang_lld)
 	}
diff --git a/java/config/config.go b/java/config/config.go
index e728b7d..1d4b242 100644
--- a/java/config/config.go
+++ b/java/config/config.go
@@ -159,7 +159,7 @@
 	pctx.HostBinToolVariable("ZipSyncCmd", "zipsync")
 	pctx.HostBinToolVariable("ApiCheckCmd", "apicheck")
 	pctx.HostBinToolVariable("D8Cmd", "d8")
-	pctx.HostBinToolVariable("R8Cmd", "r8-compat-proguard")
+	pctx.HostBinToolVariable("R8Cmd", "r8")
 	pctx.HostBinToolVariable("HiddenAPICmd", "hiddenapi")
 	pctx.HostBinToolVariable("ExtractApksCmd", "extract_apks")
 	pctx.VariableFunc("TurbineJar", func(ctx android.PackageVarContext) string {
@@ -177,7 +177,7 @@
 	pctx.HostJavaToolVariable("MetalavaJar", "metalava.jar")
 	pctx.HostJavaToolVariable("DokkaJar", "dokka.jar")
 	pctx.HostJavaToolVariable("JetifierJar", "jetifier.jar")
-	pctx.HostJavaToolVariable("R8Jar", "r8-compat-proguard.jar")
+	pctx.HostJavaToolVariable("R8Jar", "r8.jar")
 	pctx.HostJavaToolVariable("D8Jar", "d8.jar")
 
 	pctx.HostBinToolVariable("SoongJavacWrapper", "soong_javac_wrapper")
diff --git a/ui/build/config.go b/ui/build/config.go
index 5765f21..59b01b3 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -211,7 +211,7 @@
 	}
 
 	if err := fetchEnvConfig(ctx, config, bc); err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to fetch config file: %v\n", err)
+		ctx.Verbosef("Failed to fetch config file: %v\n", err)
 	}
 
 	configDirs := []string{