diff --git a/android/config.go b/android/config.go
index 0aad3bd..a9fcca5 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1426,6 +1426,10 @@
 	return !Bool(c.productVariables.KeepVndk)
 }
 
+func (c *config) VendorApiLevel() string {
+	return String(c.productVariables.VendorApiLevel)
+}
+
 func (c *deviceConfig) Arches() []Arch {
 	var arches []Arch
 	for _, target := range c.config.Targets[Android] {
diff --git a/android/defs.go b/android/defs.go
index b28d2fa..03968c1 100644
--- a/android/defs.go
+++ b/android/defs.go
@@ -232,7 +232,7 @@
 
 // ContentFromFileRuleForTests returns the content that was passed to a WriteFileRule for use
 // in tests.
-func ContentFromFileRuleForTests(t *testing.T, params TestingBuildParams) string {
+func ContentFromFileRuleForTests(t *testing.T, ctx *TestContext, params TestingBuildParams) string {
 	t.Helper()
 	if g, w := params.Rule, writeFile; g != w {
 		t.Errorf("expected params.Rule to be %q, was %q", w, g)
diff --git a/android/rule_builder.go b/android/rule_builder.go
index 5c6dffe..1a491f7 100644
--- a/android/rule_builder.go
+++ b/android/rule_builder.go
@@ -1341,9 +1341,9 @@
 
 // RuleBuilderSboxProtoForTests takes the BuildParams for the manifest passed to RuleBuilder.Sbox()
 // and returns sbox testproto generated by the RuleBuilder.
-func RuleBuilderSboxProtoForTests(t *testing.T, params TestingBuildParams) *sbox_proto.Manifest {
+func RuleBuilderSboxProtoForTests(t *testing.T, ctx *TestContext, params TestingBuildParams) *sbox_proto.Manifest {
 	t.Helper()
-	content := ContentFromFileRuleForTests(t, params)
+	content := ContentFromFileRuleForTests(t, ctx, params)
 	manifest := sbox_proto.Manifest{}
 	err := prototext.Unmarshal([]byte(content), &manifest)
 	if err != nil {
diff --git a/android/rule_builder_test.go b/android/rule_builder_test.go
index a6b3a27..63c3527 100644
--- a/android/rule_builder_test.go
+++ b/android/rule_builder_test.go
@@ -683,7 +683,7 @@
 			t.Errorf("want Deps = %q, got %q", blueprint.DepsGCC, params.Deps)
 		}
 
-		rspFile2Content := ContentFromFileRuleForTests(t, rspFile2Params)
+		rspFile2Content := ContentFromFileRuleForTests(t, result.TestContext, rspFile2Params)
 		AssertStringEquals(t, "rspFile2 content", "rsp_in2\n", rspFile2Content)
 	}
 
@@ -797,7 +797,7 @@
 		t.Run(test.name, func(t *testing.T) {
 			t.Run("sbox", func(t *testing.T) {
 				gen := result.ModuleForTests(test.name+"_sbox", "")
-				manifest := RuleBuilderSboxProtoForTests(t, gen.Output("sbox.textproto"))
+				manifest := RuleBuilderSboxProtoForTests(t, result.TestContext, gen.Output("sbox.textproto"))
 				hash := manifest.Commands[0].GetInputHash()
 
 				AssertStringEquals(t, "hash", test.expectedHash, hash)
diff --git a/android/variable.go b/android/variable.go
index 307deaf..f4c6e1c 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -226,6 +226,8 @@
 	DeviceMaxPageSizeSupported            *string  `json:",omitempty"`
 	DevicePageSizeAgnostic                *bool    `json:",omitempty"`
 
+	VendorApiLevel *string `json:",omitempty"`
+
 	RecoverySnapshotVersion *string `json:",omitempty"`
 
 	DeviceSecondaryArch        *string  `json:",omitempty"`
@@ -618,6 +620,14 @@
 	}
 }
 
+func (this *ProductVariables) GetBuildFlagBool(flag string) bool {
+	val, ok := this.BuildFlags[flag]
+	if !ok {
+		return false
+	}
+	return val == "true"
+}
+
 // ProductConfigContext requires the access to the Module to get product config properties.
 type ProductConfigContext interface {
 	Module() Module
diff --git a/apex/apex_test.go b/apex/apex_test.go
index ab0c130..f14ab8a 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -597,13 +597,15 @@
 		t.Errorf("Could not find all expected symlinks! foo: %t, foo_link_64: %t. Command was %s", found_foo, found_foo_link_64, copyCmds)
 	}
 
-	fullDepsInfo := strings.Split(ctx.ModuleForTests("myapex", "android_common_myapex").Output("depsinfo/fulllist.txt").Args["content"], "\\n")
+	fullDepsInfo := strings.Split(android.ContentFromFileRuleForTests(t, ctx,
+		ctx.ModuleForTests("myapex", "android_common_myapex").Output("depsinfo/fulllist.txt")), "\n")
 	ensureListContains(t, fullDepsInfo, "  myjar(minSdkVersion:(no version)) <- myapex")
 	ensureListContains(t, fullDepsInfo, "  mylib2(minSdkVersion:(no version)) <- mylib")
 	ensureListContains(t, fullDepsInfo, "  myotherjar(minSdkVersion:(no version)) <- myjar")
 	ensureListContains(t, fullDepsInfo, "  mysharedjar(minSdkVersion:(no version)) (external) <- myjar")
 
-	flatDepsInfo := strings.Split(ctx.ModuleForTests("myapex", "android_common_myapex").Output("depsinfo/flatlist.txt").Args["content"], "\\n")
+	flatDepsInfo := strings.Split(android.ContentFromFileRuleForTests(t, ctx,
+		ctx.ModuleForTests("myapex", "android_common_myapex").Output("depsinfo/flatlist.txt")), "\n")
 	ensureListContains(t, flatDepsInfo, "myjar(minSdkVersion:(no version))")
 	ensureListContains(t, flatDepsInfo, "mylib2(minSdkVersion:(no version))")
 	ensureListContains(t, flatDepsInfo, "myotherjar(minSdkVersion:(no version))")
@@ -1283,10 +1285,12 @@
 	// Ensure that libfoo stubs is not linking to libbar (since it is a stubs)
 	ensureNotContains(t, libFooStubsLdFlags, "libbar.so")
 
-	fullDepsInfo := strings.Split(ctx.ModuleForTests("myapex2", "android_common_myapex2").Output("depsinfo/fulllist.txt").Args["content"], "\\n")
+	fullDepsInfo := strings.Split(android.ContentFromFileRuleForTests(t, ctx,
+		ctx.ModuleForTests("myapex2", "android_common_myapex2").Output("depsinfo/fulllist.txt")), "\n")
 	ensureListContains(t, fullDepsInfo, "  libfoo(minSdkVersion:(no version)) (external) <- mylib")
 
-	flatDepsInfo := strings.Split(ctx.ModuleForTests("myapex2", "android_common_myapex2").Output("depsinfo/flatlist.txt").Args["content"], "\\n")
+	flatDepsInfo := strings.Split(android.ContentFromFileRuleForTests(t, ctx,
+		ctx.ModuleForTests("myapex2", "android_common_myapex2").Output("depsinfo/flatlist.txt")), "\n")
 	ensureListContains(t, flatDepsInfo, "libfoo(minSdkVersion:(no version)) (external)")
 }
 
@@ -2032,7 +2036,8 @@
 		"out/soong/.intermediates/myapex2/android_common_myapex2/depsinfo/flatlist.txt")
 
 	myapex := ctx.ModuleForTests("myapex", "android_common_myapex")
-	flatlist := strings.Split(myapex.Output("depsinfo/flatlist.txt").BuildParams.Args["content"], "\\n")
+	flatlist := strings.Split(android.ContentFromFileRuleForTests(t, ctx,
+		myapex.Output("depsinfo/flatlist.txt")), "\n")
 	android.AssertStringListContains(t, "deps with stubs should be tracked in depsinfo as external dep",
 		flatlist, "libbar(minSdkVersion:(no version)) (external)")
 	android.AssertStringListDoesNotContain(t, "do not track if not available for platform",
@@ -8222,7 +8227,7 @@
 		`, withManifestPackageNameOverrides([]string{"AppFoo:com.android.foo"}))
 
 	bundleConfigRule := ctx.ModuleForTests("myapex", "android_common_myapex").Output("bundle_config.json")
-	content := bundleConfigRule.Args["content"]
+	content := android.ContentFromFileRuleForTests(t, ctx, bundleConfigRule)
 
 	ensureContains(t, content, `"compression":{"uncompressed_glob":["apex_payload.img","apex_manifest.*"]}`)
 	ensureContains(t, content, `"apex_config":{"apex_embedded_apk_config":[{"package_name":"com.android.foo","path":"app/AppFoo@TEST.BUILD_ID/AppFoo.apk"}]}`)
@@ -8249,7 +8254,7 @@
 		}`)
 	mod := ctx.ModuleForTests("myapex", "android_common_myapex")
 	bundleConfigRule := mod.Output("bundle_config.json")
-	content := bundleConfigRule.Args["content"]
+	content := android.ContentFromFileRuleForTests(t, ctx, bundleConfigRule)
 	ensureContains(t, content, `"compression":{"uncompressed_glob":["apex_payload.img","apex_manifest.*"]}`)
 	s := mod.Rule("apexRule").Args["copy_commands"]
 	copyCmds := regexp.MustCompile(" *&& *").Split(s, -1)
@@ -9194,7 +9199,7 @@
 	`)
 
 	myapex := ctx.ModuleForTests("myapex", "android_common_myapex")
-	content := myapex.Output("apexkeys.txt").BuildParams.Args["content"]
+	content := android.ContentFromFileRuleForTests(t, ctx, myapex.Output("apexkeys.txt"))
 	ensureContains(t, content, `name="myapex.apex" public_key="vendor/foo/devkeys/testkey.avbpubkey" private_key="vendor/foo/devkeys/testkey.pem" container_certificate="vendor/foo/devkeys/test.x509.pem" container_private_key="vendor/foo/devkeys/test.pk8" partition="system" sign_tool="sign_myapex"`)
 }
 
@@ -9234,9 +9239,11 @@
 		}
 	`)
 
-	content := ctx.ModuleForTests("myapex", "android_common_myapex").Output("apexkeys.txt").BuildParams.Args["content"]
+	content := android.ContentFromFileRuleForTests(t, ctx,
+		ctx.ModuleForTests("myapex", "android_common_myapex").Output("apexkeys.txt"))
 	ensureContains(t, content, `name="myapex.apex" public_key="vendor/foo/devkeys/testkey.avbpubkey" private_key="vendor/foo/devkeys/testkey.pem" container_certificate="vendor/foo/devkeys/test.x509.pem" container_private_key="vendor/foo/devkeys/test.pk8" partition="system" sign_tool="sign_myapex"`)
-	content = ctx.ModuleForTests("myapex_set", "android_common_myapex_set").Output("apexkeys.txt").BuildParams.Args["content"]
+	content = android.ContentFromFileRuleForTests(t, ctx,
+		ctx.ModuleForTests("myapex_set", "android_common_myapex_set").Output("apexkeys.txt"))
 	ensureContains(t, content, `name="myapex_set.apex" public_key="PRESIGNED" private_key="PRESIGNED" container_certificate="PRESIGNED" container_private_key="PRESIGNED" partition="system"`)
 }
 
diff --git a/cc/afdo.go b/cc/afdo.go
index 91cf0b8..e7dea0e 100644
--- a/cc/afdo.go
+++ b/cc/afdo.go
@@ -64,6 +64,13 @@
 	return []interface{}{&afdo.Properties}
 }
 
+func (afdo *afdo) begin(ctx BaseModuleContext) {
+	// Disable on eng builds for faster build.
+	if ctx.Config().Eng() {
+		afdo.Properties.Afdo = false
+	}
+}
+
 // afdoEnabled returns true for binaries and shared libraries
 // that set afdo prop to True and there is a profile available
 func (afdo *afdo) afdoEnabled() bool {
diff --git a/cc/cc.go b/cc/cc.go
index 867a59c..2e42761 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -2401,6 +2401,9 @@
 	if c.coverage != nil {
 		c.coverage.begin(ctx)
 	}
+	if c.afdo != nil {
+		c.afdo.begin(ctx)
+	}
 	if c.lto != nil {
 		c.lto.begin(ctx)
 	}
diff --git a/cc/cc_test.go b/cc/cc_test.go
index ed13e22..710b72b 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -40,6 +40,7 @@
 var prepareForCcTest = android.GroupFixturePreparers(
 	PrepareForTestWithCcIncludeVndk,
 	android.FixtureModifyProductVariables(func(variables android.FixtureProductVariables) {
+		variables.VendorApiLevel = StringPtr("202404")
 		variables.DeviceVndkVersion = StringPtr("current")
 		variables.Platform_vndk_version = StringPtr("29")
 	}),
@@ -341,9 +342,9 @@
 	}
 }
 
-func checkWriteFileOutput(t *testing.T, params android.TestingBuildParams, expected []string) {
+func checkWriteFileOutput(t *testing.T, ctx *android.TestContext, params android.TestingBuildParams, expected []string) {
 	t.Helper()
-	content := android.ContentFromFileRuleForTests(t, params)
+	content := android.ContentFromFileRuleForTests(t, ctx, params)
 	actual := strings.FieldsFunc(content, func(r rune) bool { return r == '\n' })
 	assertArrayString(t, actual, expected)
 }
@@ -351,7 +352,7 @@
 func checkVndkOutput(t *testing.T, ctx *android.TestContext, output string, expected []string) {
 	t.Helper()
 	vndkSnapshot := ctx.SingletonForTests("vndk-snapshot")
-	checkWriteFileOutput(t, vndkSnapshot.Output(output), expected)
+	checkWriteFileOutput(t, ctx, vndkSnapshot.Output(output), expected)
 }
 
 func checkVndkLibrariesOutput(t *testing.T, ctx *android.TestContext, module string, expected []string) {
@@ -2131,11 +2132,13 @@
 	ensureStringContains(t, vendor_cflags, "-D__ANDROID_VNDK__")
 	ensureStringContains(t, vendor_cflags, "-D__ANDROID_VENDOR__")
 	ensureStringNotContains(t, vendor_cflags, "-D__ANDROID_PRODUCT__")
+	ensureStringContains(t, vendor_cflags, "-D__ANDROID_VENDOR_API__=202404")
 
 	product_cflags := product_static.Rule("cc").Args["cFlags"]
 	ensureStringContains(t, product_cflags, "-D__ANDROID_VNDK__")
 	ensureStringContains(t, product_cflags, "-D__ANDROID_PRODUCT__")
 	ensureStringNotContains(t, product_cflags, "-D__ANDROID_VENDOR__")
+	ensureStringNotContains(t, product_cflags, "-D__ANDROID_VENDOR_API__=202404")
 }
 
 func TestEnforceProductVndkVersionErrors(t *testing.T) {
@@ -4302,7 +4305,7 @@
 		libfoo.Rule("aidl_library").Implicits,
 	)
 
-	manifest := android.RuleBuilderSboxProtoForTests(t, libfoo.Output("aidl_library.sbox.textproto"))
+	manifest := android.RuleBuilderSboxProtoForTests(t, ctx, libfoo.Output("aidl_library.sbox.textproto"))
 	aidlCommand := manifest.Commands[0].GetCommand()
 
 	expectedAidlFlags := "-Ipackage_foo/a -Ipackage_bar/x"
@@ -4337,7 +4340,7 @@
 	`)
 
 	libfoo := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_static")
-	manifest := android.RuleBuilderSboxProtoForTests(t, libfoo.Output("aidl.sbox.textproto"))
+	manifest := android.RuleBuilderSboxProtoForTests(t, ctx.TestContext, libfoo.Output("aidl.sbox.textproto"))
 	aidlCommand := manifest.Commands[0].GetCommand()
 	expectedAidlFlag := "-Werror"
 	if !strings.Contains(aidlCommand, expectedAidlFlag) {
@@ -4388,7 +4391,7 @@
 				}
 			`)
 			libfoo := ctx.ModuleForTests("libfoo", tc.variant)
-			manifest := android.RuleBuilderSboxProtoForTests(t, libfoo.Output("aidl.sbox.textproto"))
+			manifest := android.RuleBuilderSboxProtoForTests(t, ctx, libfoo.Output("aidl.sbox.textproto"))
 			aidlCommand := manifest.Commands[0].GetCommand()
 			expectedAidlFlag := "--min_sdk_version=" + tc.expected
 			if !strings.Contains(aidlCommand, expectedAidlFlag) {
diff --git a/cc/compiler.go b/cc/compiler.go
index 490d3cc..bb7885b 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -406,6 +406,15 @@
 		flags.Global.CommonFlags = append(flags.Global.CommonFlags, "-D__ANDROID_VNDK__")
 		if ctx.inVendor() {
 			flags.Global.CommonFlags = append(flags.Global.CommonFlags, "-D__ANDROID_VENDOR__")
+
+			vendorApiLevel := ctx.Config().VendorApiLevel()
+			if vendorApiLevel == "" {
+				// TODO(b/314036847): This is a fallback for UDC targets.
+				// This must be a build failure when UDC is no longer built
+				// from this source tree.
+				vendorApiLevel = ctx.Config().PlatformSdkVersion().String()
+			}
+			flags.Global.CommonFlags = append(flags.Global.CommonFlags, "-D__ANDROID_VENDOR_API__="+vendorApiLevel)
 		} else if ctx.inProduct() {
 			flags.Global.CommonFlags = append(flags.Global.CommonFlags, "-D__ANDROID_PRODUCT__")
 		}
diff --git a/cc/config/riscv64_device.go b/cc/config/riscv64_device.go
index e820260..0964015 100644
--- a/cc/config/riscv64_device.go
+++ b/cc/config/riscv64_device.go
@@ -39,6 +39,9 @@
 		// Equivalent to "-munaligned-access", but our clang doesn't have that yet.
 		"-Xclang -target-feature -Xclang +unaligned-scalar-mem",
 		"-Xclang -target-feature -Xclang +unaligned-vector-mem",
+		// We should change the default for this in clang, but for now...
+		// (https://github.com/google/android-riscv64/issues/124)
+		"-mllvm -jump-is-expensive=false",
 	}
 
 	riscv64Lldflags = append(riscv64Ldflags,
diff --git a/cc/gen_test.go b/cc/gen_test.go
index 85df333..439f0a9 100644
--- a/cc/gen_test.go
+++ b/cc/gen_test.go
@@ -67,7 +67,7 @@
 			t.Errorf("missing aidl includes in global flags")
 		}
 
-		aidlCommand := android.RuleBuilderSboxProtoForTests(t, aidlManifest).Commands[0].GetCommand()
+		aidlCommand := android.RuleBuilderSboxProtoForTests(t, ctx, aidlManifest).Commands[0].GetCommand()
 		if !strings.Contains(aidlCommand, "-Isub") {
 			t.Errorf("aidl command for c.aidl should contain \"-Isub\", but was %q", aidlCommand)
 		}
diff --git a/cc/genrule_test.go b/cc/genrule_test.go
index 0d16e62..9295244 100644
--- a/cc/genrule_test.go
+++ b/cc/genrule_test.go
@@ -178,7 +178,7 @@
 				android.OptionalFixturePreparer(tt.preparer),
 			).RunTestWithBp(t, bp)
 			gen := result.ModuleForTests("gen", tt.variant)
-			sboxProto := android.RuleBuilderSboxProtoForTests(t, gen.Output("genrule.sbox.textproto"))
+			sboxProto := android.RuleBuilderSboxProtoForTests(t, result.TestContext, gen.Output("genrule.sbox.textproto"))
 			cmd := *sboxProto.Commands[0].Command
 			android.AssertStringDoesContain(t, "incorrect CC_ARCH", cmd, "CC_ARCH="+tt.arch+" ")
 			android.AssertStringDoesContain(t, "incorrect CC_NATIVE_BRIDGE", cmd, "CC_NATIVE_BRIDGE="+tt.nativeBridge+" ")
diff --git a/cc/lto.go b/cc/lto.go
index d2a43d2..8b0880c 100644
--- a/cc/lto.go
+++ b/cc/lto.go
@@ -116,7 +116,8 @@
 		// better dead code elimination and CFG simplification, but do
 		// not perform costly optimizations for a balance between compile
 		// time, binary size and performance.
-		if !lto.ThinLTO() {
+		// Apply the same for Eng builds as well.
+		if !lto.ThinLTO() || ctx.Config().Eng() {
 			ltoLdFlags = append(ltoLdFlags, "-Wl,--lto-O0")
 		}
 
diff --git a/cc/testing.go b/cc/testing.go
index 71d986b..b1583f1 100644
--- a/cc/testing.go
+++ b/cc/testing.go
@@ -797,7 +797,7 @@
 func checkOverrides(t *testing.T, ctx *android.TestContext, singleton android.TestingSingleton, jsonPath string, expected []string) {
 	t.Helper()
 	out := singleton.MaybeOutput(jsonPath)
-	content := android.ContentFromFileRuleForTests(t, out)
+	content := android.ContentFromFileRuleForTests(t, ctx, out)
 
 	var flags snapshotJsonFlags
 	if err := json.Unmarshal([]byte(content), &flags); err != nil {
diff --git a/cc/vendor_snapshot_test.go b/cc/vendor_snapshot_test.go
index c5431b3..890a533 100644
--- a/cc/vendor_snapshot_test.go
+++ b/cc/vendor_snapshot_test.go
@@ -23,13 +23,14 @@
 	"testing"
 )
 
-func checkJsonContents(t *testing.T, ctx android.TestingSingleton, jsonPath string, key string, value string) {
-	jsonOut := ctx.MaybeOutput(jsonPath)
+func checkJsonContents(t *testing.T, ctx *android.TestContext, snapshotSingleton android.TestingSingleton, jsonPath string, key string, value string) {
+	jsonOut := snapshotSingleton.MaybeOutput(jsonPath)
 	if jsonOut.Rule == nil {
 		t.Errorf("%q expected but not found", jsonPath)
 		return
 	}
-	if !strings.Contains(jsonOut.Args["content"], fmt.Sprintf("%q:%q", key, value)) {
+	content := android.ContentFromFileRuleForTests(t, ctx, jsonOut)
+	if !strings.Contains(content, fmt.Sprintf("%q:%q", key, value)) {
 		t.Errorf("%q must include %q:%q but it only has %v", jsonPath, key, value, jsonOut.Args["content"])
 	}
 }
@@ -167,8 +168,8 @@
 			filepath.Join(staticDir, "libvendor_available.a.json"),
 			filepath.Join(staticDir, "libvendor_available.cfi.a.json"))
 
-		checkJsonContents(t, snapshotSingleton, filepath.Join(staticDir, "libb.a.json"), "MinSdkVersion", "apex_inherit")
-		checkJsonContents(t, snapshotSingleton, filepath.Join(staticDir, "libvendor_available.a.json"), "MinSdkVersion", "29")
+		checkJsonContents(t, ctx, snapshotSingleton, filepath.Join(staticDir, "libb.a.json"), "MinSdkVersion", "apex_inherit")
+		checkJsonContents(t, ctx, snapshotSingleton, filepath.Join(staticDir, "libvendor_available.a.json"), "MinSdkVersion", "29")
 
 		// For binary executables, all vendor:true and vendor_available modules are captured.
 		if archType == "arm64" {
diff --git a/genrule/genrule_test.go b/genrule/genrule_test.go
index 7c14531..4cff4b8 100644
--- a/genrule/genrule_test.go
+++ b/genrule/genrule_test.go
@@ -543,7 +543,7 @@
 	for _, test := range testcases {
 		t.Run(test.name, func(t *testing.T) {
 			gen := result.ModuleForTests(test.name, "")
-			manifest := android.RuleBuilderSboxProtoForTests(t, gen.Output("genrule.sbox.textproto"))
+			manifest := android.RuleBuilderSboxProtoForTests(t, result.TestContext, gen.Output("genrule.sbox.textproto"))
 			hash := manifest.Commands[0].GetInputHash()
 
 			android.AssertStringEquals(t, "hash", test.expectedHash, hash)
diff --git a/java/droidstubs_test.go b/java/droidstubs_test.go
index f86e1ac..7b89dde 100644
--- a/java/droidstubs_test.go
+++ b/java/droidstubs_test.go
@@ -84,7 +84,7 @@
 	for _, c := range testcases {
 		m := ctx.ModuleForTests(c.moduleName, "android_common")
 		manifest := m.Output("metalava.sbox.textproto")
-		sboxProto := android.RuleBuilderSboxProtoForTests(t, manifest)
+		sboxProto := android.RuleBuilderSboxProtoForTests(t, ctx, manifest)
 		cmdline := String(sboxProto.Commands[0].Command)
 		android.AssertStringContainsEquals(t, "api-versions generation flag", cmdline, "--generate-api-levels", c.generate_xml)
 		if c.expectedJarFilename != "" {
@@ -133,7 +133,7 @@
 
 	m := ctx.ModuleForTests("foo-stubs", "android_common")
 	manifest := m.Output("metalava.sbox.textproto")
-	cmd := String(android.RuleBuilderSboxProtoForTests(t, manifest).Commands[0].Command)
+	cmd := String(android.RuleBuilderSboxProtoForTests(t, ctx, manifest).Commands[0].Command)
 	r := regexp.MustCompile(`--android-jar-pattern [^ ]+/android.jar`)
 	return r.FindAllString(cmd, -1)
 }
@@ -212,7 +212,7 @@
 		t.Errorf("Expected inputs %q, got %q", w, g)
 	}
 
-	manifest := android.RuleBuilderSboxProtoForTests(t, m.Output("metalava.sbox.textproto"))
+	manifest := android.RuleBuilderSboxProtoForTests(t, ctx, m.Output("metalava.sbox.textproto"))
 	if g, w := manifest.Commands[0].GetCommand(), "reference __SBOX_SANDBOX_DIR__/out/.intermediates/foo/gen/foo.txt"; !strings.Contains(g, w) {
 		t.Errorf("Expected command to contain %q, got %q", w, g)
 	}
@@ -302,7 +302,7 @@
 		})
 	m := ctx.ModuleForTests("baz-stubs", "android_common")
 	manifest := m.Output("metalava.sbox.textproto")
-	cmdline := String(android.RuleBuilderSboxProtoForTests(t, manifest).Commands[0].Command)
+	cmdline := String(android.RuleBuilderSboxProtoForTests(t, ctx, manifest).Commands[0].Command)
 	android.AssertStringDoesContain(t, "sdk-extensions-root present", cmdline, "--sdk-extensions-root sdk/extensions")
 	android.AssertStringDoesContain(t, "sdk-extensions-info present", cmdline, "--sdk-extensions-info sdk/extensions/info.txt")
 }
@@ -434,6 +434,6 @@
 
 	m := result.ModuleForTests("foo", "android_common")
 	manifest := m.Output("metalava.sbox.textproto")
-	cmdline := String(android.RuleBuilderSboxProtoForTests(t, manifest).Commands[0].Command)
+	cmdline := String(android.RuleBuilderSboxProtoForTests(t, result.TestContext, manifest).Commands[0].Command)
 	android.AssertStringDoesContain(t, "flagged api hide command not included", cmdline, "--hide-annotation android.annotation.FlaggedApi")
 }
diff --git a/java/java_test.go b/java/java_test.go
index 81119a7..0c750eb 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -1921,7 +1921,7 @@
 	for _, c := range testcases {
 		m := ctx.ModuleForTests(c.moduleName, "android_common")
 		manifest := m.Output("metalava.sbox.textproto")
-		sboxProto := android.RuleBuilderSboxProtoForTests(t, manifest)
+		sboxProto := android.RuleBuilderSboxProtoForTests(t, ctx.TestContext, manifest)
 		manifestCommand := sboxProto.Commands[0].GetCommand()
 		sourceFilesFlag := "--source-files " + strings.Join(c.sourceTextFileDirs, " ")
 		android.AssertStringDoesContain(t, "source text files not present", manifestCommand, sourceFilesFlag)
@@ -2026,7 +2026,7 @@
 	for _, c := range testcases {
 		m := ctx.ModuleForTests(c.moduleName, "android_common")
 		manifest := m.Output("metalava.sbox.textproto")
-		sboxProto := android.RuleBuilderSboxProtoForTests(t, manifest)
+		sboxProto := android.RuleBuilderSboxProtoForTests(t, ctx.TestContext, manifest)
 		manifestCommand := sboxProto.Commands[0].GetCommand()
 		sourceFilesFlag := "--source-files " + strings.Join(c.sourceTextFileDirs, " ")
 		android.AssertStringDoesContain(t, "source text files not present", manifestCommand, sourceFilesFlag)
@@ -2316,7 +2316,7 @@
 
 	m := ctx.ModuleForTests("bar1", "android_common")
 	manifest := m.Output("metalava.sbox.textproto")
-	sboxProto := android.RuleBuilderSboxProtoForTests(t, manifest)
+	sboxProto := android.RuleBuilderSboxProtoForTests(t, ctx.TestContext, manifest)
 	manifestCommand := sboxProto.Commands[0].GetCommand()
 	android.AssertStringDoesContain(t, "Command expected to contain full_api_surface_stub output jar", manifestCommand, "lib1.jar")
 }
@@ -2480,7 +2480,7 @@
 	`)
 	m := ctx.ModuleForTests("foo", "android_common")
 	manifest := m.Output("metalava.sbox.textproto")
-	sboxProto := android.RuleBuilderSboxProtoForTests(t, manifest)
+	sboxProto := android.RuleBuilderSboxProtoForTests(t, ctx.TestContext, manifest)
 	manifestCommand := sboxProto.Commands[0].GetCommand()
 	sourceFilesFlag := "--source-files current.txt"
 	android.AssertStringDoesContain(t, "source text files not present", manifestCommand, sourceFilesFlag)
@@ -2501,7 +2501,7 @@
 	`)
 	m := ctx.ModuleForTests("foo", "android_common")
 	manifest := m.Output("metalava.sbox.textproto")
-	sboxProto := android.RuleBuilderSboxProtoForTests(t, manifest)
+	sboxProto := android.RuleBuilderSboxProtoForTests(t, ctx, manifest)
 	manifestCommand := sboxProto.Commands[0].GetCommand()
 
 	// Api files are sorted from the narrowest api scope to the widest api scope.
@@ -2543,7 +2543,7 @@
 	`)
 	m := result.ModuleForTests(apiScopePublic.apiLibraryModuleName("foo"), "android_common")
 	manifest := m.Output("metalava.sbox.textproto")
-	sboxProto := android.RuleBuilderSboxProtoForTests(t, manifest)
+	sboxProto := android.RuleBuilderSboxProtoForTests(t, result.TestContext, manifest)
 	manifestCommand := sboxProto.Commands[0].GetCommand()
 	classPathFlag := "--classpath __SBOX_SANDBOX_DIR__/out/.intermediates/bar/android_common/turbine-combined/bar.jar"
 	android.AssertStringDoesContain(t, "command expected to contain classpath flag", manifestCommand, classPathFlag)
diff --git a/java/lint_test.go b/java/lint_test.go
index ec901aa..5e6b8bc 100644
--- a/java/lint_test.go
+++ b/java/lint_test.go
@@ -39,7 +39,7 @@
 
 	foo := ctx.ModuleForTests("foo", "android_common")
 
-	sboxProto := android.RuleBuilderSboxProtoForTests(t, foo.Output("lint.sbox.textproto"))
+	sboxProto := android.RuleBuilderSboxProtoForTests(t, ctx, foo.Output("lint.sbox.textproto"))
 	if !strings.Contains(*sboxProto.Commands[0].Command, "--baseline lint-baseline.xml") {
 		t.Error("did not pass --baseline flag")
 	}
@@ -61,7 +61,7 @@
 
 	foo := ctx.ModuleForTests("foo", "android_common")
 
-	sboxProto := android.RuleBuilderSboxProtoForTests(t, foo.Output("lint.sbox.textproto"))
+	sboxProto := android.RuleBuilderSboxProtoForTests(t, ctx, foo.Output("lint.sbox.textproto"))
 	if strings.Contains(*sboxProto.Commands[0].Command, "--baseline") {
 		t.Error("passed --baseline flag for non existent file")
 	}
@@ -108,7 +108,7 @@
 
 	foo := ctx.ModuleForTests("foo", "android_common")
 
-	sboxProto := android.RuleBuilderSboxProtoForTests(t, foo.Output("lint.sbox.textproto"))
+	sboxProto := android.RuleBuilderSboxProtoForTests(t, ctx, foo.Output("lint.sbox.textproto"))
 	if !strings.Contains(*sboxProto.Commands[0].Command, "--baseline mybaseline.xml") {
 		t.Error("did not use the correct file for baseline")
 	}
@@ -276,7 +276,7 @@
 			RunTestWithBp(t, thisBp)
 
 		foo := result.ModuleForTests("foo", "android_common")
-		sboxProto := android.RuleBuilderSboxProtoForTests(t, foo.Output("lint.sbox.textproto"))
+		sboxProto := android.RuleBuilderSboxProtoForTests(t, result.TestContext, foo.Output("lint.sbox.textproto"))
 		if !strings.Contains(*sboxProto.Commands[0].Command, "/"+testCase.expected_file) {
 			t.Error("did not use full api database for case", testCase)
 		}
diff --git a/rust/bindgen.go b/rust/bindgen.go
index ffe532f..1cc1574 100644
--- a/rust/bindgen.go
+++ b/rust/bindgen.go
@@ -174,6 +174,15 @@
 		cflags = append(cflags, "-D__ANDROID_VNDK__")
 		if ctx.RustModule().InVendor() {
 			cflags = append(cflags, "-D__ANDROID_VENDOR__")
+
+			vendorApiLevel := ctx.Config().VendorApiLevel()
+			if vendorApiLevel == "" {
+				// TODO(b/314036847): This is a fallback for UDC targets.
+				// This must be a build failure when UDC is no longer built
+				// from this source tree.
+				vendorApiLevel = ctx.Config().PlatformSdkVersion().String()
+			}
+			cflags = append(cflags, "-D__ANDROID_VENDOR_API__="+vendorApiLevel)
 		} else if ctx.RustModule().InProduct() {
 			cflags = append(cflags, "-D__ANDROID_PRODUCT__")
 		}
diff --git a/ui/build/build.go b/ui/build/build.go
index 9d5c330..54a4c27 100644
--- a/ui/build/build.go
+++ b/ui/build/build.go
@@ -283,11 +283,16 @@
 	}
 
 	rbeCh := make(chan bool)
+	var rbePanic any
 	if config.StartRBE() {
 		cleanupRBELogsDir(ctx, config)
+		checkRBERequirements(ctx, config)
 		go func() {
+			defer func() {
+				rbePanic = recover()
+				close(rbeCh)
+			}()
 			startRBE(ctx, config)
-			close(rbeCh)
 		}()
 		defer DumpRBEMetrics(ctx, config, filepath.Join(config.LogsDir(), "rbe_metrics.pb"))
 	} else {
@@ -345,6 +350,11 @@
 	}
 
 	<-rbeCh
+	if rbePanic != nil {
+		// If there was a ctx.Fatal in startRBE, rethrow it.
+		panic(rbePanic)
+	}
+
 	if what&RunNinja != 0 {
 		if what&RunKati != 0 {
 			installCleanIfNecessary(ctx, config)
diff --git a/ui/build/rbe.go b/ui/build/rbe.go
index 19a54df..fa04207 100644
--- a/ui/build/rbe.go
+++ b/ui/build/rbe.go
@@ -95,14 +95,10 @@
 	}
 }
 
-func startRBE(ctx Context, config Config) {
+func checkRBERequirements(ctx Context, config Config) {
 	if !config.GoogleProdCredsExist() && prodCredsAuthType(config) {
 		ctx.Fatalf("Unable to start RBE reproxy\nFAILED: Missing LOAS credentials.")
 	}
-	ctx.BeginTrace(metrics.RunSetupTool, "rbe_bootstrap")
-	defer ctx.EndTrace()
-
-	ctx.Status.Status("Starting rbe...")
 
 	if u := ulimitOrFatal(ctx, config, "-u"); u < rbeLeastNProcs {
 		ctx.Fatalf("max user processes is insufficient: %d; want >= %d.\n", u, rbeLeastNProcs)
@@ -115,6 +111,13 @@
 			ctx.Fatalf("Unable to create logs dir (%v) for RBE: %v", config.rbeProxyLogsDir, err)
 		}
 	}
+}
+
+func startRBE(ctx Context, config Config) {
+	ctx.BeginTrace(metrics.RunSetupTool, "rbe_bootstrap")
+	defer ctx.EndTrace()
+
+	ctx.Status.Status("Starting rbe...")
 
 	cmd := Command(ctx, config, "startRBE bootstrap", rbeCommand(ctx, config, bootstrapCmd))