diff --git a/apex/apex.go b/apex/apex.go
index fcac3ab..a07576a 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -2066,15 +2066,23 @@
 	requireNativeLibs []string
 
 	handleSpecialLibs bool
+
+	// if true, raise error on duplicate apexFile
+	checkDuplicate bool
 }
 
-func (vctx *visitorContext) normalizeFileInfo() {
+func (vctx *visitorContext) normalizeFileInfo(mctx android.ModuleContext) {
 	encountered := make(map[string]apexFile)
 	for _, f := range vctx.filesInfo {
 		dest := filepath.Join(f.installDir, f.builtFile.Base())
 		if e, ok := encountered[dest]; !ok {
 			encountered[dest] = f
 		} else {
+			if vctx.checkDuplicate && f.builtFile.String() != e.builtFile.String() {
+				mctx.ModuleErrorf("apex file %v is provided by two different files %v and %v",
+					dest, e.builtFile, f.builtFile)
+				return
+			}
 			// If a module is directly included and also transitively depended on
 			// consider it as directly included.
 			e.transitiveDep = e.transitiveDep && f.transitiveDep
@@ -2433,6 +2441,25 @@
 	return false
 }
 
+func (a *apexBundle) shouldCheckDuplicate(ctx android.ModuleContext) bool {
+	// TODO(b/263308293) remove this
+	if a.properties.IsCoverageVariant {
+		return false
+	}
+	// TODO(b/263308515) remove this
+	if a.testApex {
+		return false
+	}
+	// TODO(b/263309864) remove this
+	if a.Host() {
+		return false
+	}
+	if a.Device() && ctx.DeviceConfig().DeviceArch() == "" {
+		return false
+	}
+	return true
+}
+
 // Creates build rules for an APEX. It consists of the following major steps:
 //
 // 1) do some validity checks such as apex_available, min_sdk_version, etc.
@@ -2453,9 +2480,12 @@
 
 	// TODO(jiyong): do this using WalkPayloadDeps
 	// TODO(jiyong): make this clean!!!
-	vctx := visitorContext{handleSpecialLibs: !android.Bool(a.properties.Ignore_system_library_special_case)}
+	vctx := visitorContext{
+		handleSpecialLibs: !android.Bool(a.properties.Ignore_system_library_special_case),
+		checkDuplicate:    a.shouldCheckDuplicate(ctx),
+	}
 	ctx.WalkDepsBlueprint(func(child, parent blueprint.Module) bool { return a.depVisitor(&vctx, ctx, child, parent) })
-	vctx.normalizeFileInfo()
+	vctx.normalizeFileInfo(ctx)
 	if a.privateKeyFile == nil {
 		ctx.PropertyErrorf("key", "private_key for %q could not be found", String(a.overridableProperties.Key))
 		return
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 499d753..33fce7c 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -3420,11 +3420,34 @@
 	isLink bool
 }
 
+func (f fileInApex) String() string {
+	return f.src + ":" + f.path
+}
+
+func (f fileInApex) match(expectation string) bool {
+	parts := strings.Split(expectation, ":")
+	if len(parts) == 1 {
+		match, _ := path.Match(parts[0], f.path)
+		return match
+	}
+	if len(parts) == 2 {
+		matchSrc, _ := path.Match(parts[0], f.src)
+		matchDst, _ := path.Match(parts[1], f.path)
+		return matchSrc && matchDst
+	}
+	panic("invalid expected file specification: " + expectation)
+}
+
 func getFiles(t *testing.T, ctx *android.TestContext, moduleName, variant string) []fileInApex {
 	t.Helper()
-	apexRule := ctx.ModuleForTests(moduleName, variant).Rule("apexRule")
+	module := ctx.ModuleForTests(moduleName, variant)
+	apexRule := module.MaybeRule("apexRule")
+	apexDir := "/image.apex/"
+	if apexRule.Rule == nil {
+		apexRule = module.Rule("zipApexRule")
+		apexDir = "/image.zipapex/"
+	}
 	copyCmds := apexRule.Args["copy_commands"]
-	imageApexDir := "/image.apex/"
 	var ret []fileInApex
 	for _, cmd := range strings.Split(copyCmds, "&&") {
 		cmd = strings.TrimSpace(cmd)
@@ -3455,11 +3478,11 @@
 			t.Fatalf("copyCmds should contain mkdir/cp commands only: %q", cmd)
 		}
 		if dst != "" {
-			index := strings.Index(dst, imageApexDir)
+			index := strings.Index(dst, apexDir)
 			if index == -1 {
-				t.Fatal("copyCmds should copy a file to image.apex/", cmd)
+				t.Fatal("copyCmds should copy a file to "+apexDir, cmd)
 			}
-			dstFile := dst[index+len(imageApexDir):]
+			dstFile := dst[index+len(apexDir):]
 			ret = append(ret, fileInApex{path: dstFile, src: src, isLink: isLink})
 		}
 	}
@@ -3472,16 +3495,16 @@
 	var surplus []string
 	filesMatched := make(map[string]bool)
 	for _, file := range getFiles(t, ctx, moduleName, variant) {
-		mactchFound := false
+		matchFound := false
 		for _, expected := range files {
-			if matched, _ := path.Match(expected, file.path); matched {
+			if file.match(expected) {
+				matchFound = true
 				filesMatched[expected] = true
-				mactchFound = true
 				break
 			}
 		}
-		if !mactchFound {
-			surplus = append(surplus, file.path)
+		if !matchFound {
+			surplus = append(surplus, file.String())
 		}
 	}
 
@@ -3974,6 +3997,11 @@
 	apexManifestRule := ctx.ModuleForTests("com.android.vndk.current", "android_common_image").Rule("apexManifestRule")
 	provideNativeLibs := names(apexManifestRule.Args["provideNativeLibs"])
 	ensureListEmpty(t, provideNativeLibs)
+	ensureExactContents(t, ctx, "com.android.vndk.current", "android_common_image", []string{
+		"out/soong/.intermediates/libz/android_vendor.29_arm64_armv8-a_shared/libz.so:lib64/libz.so",
+		"out/soong/.intermediates/libz/android_vendor.29_arm_armv7-a-neon_shared/libz.so:lib/libz.so",
+		"*/*",
+	})
 }
 
 func TestDependenciesInApexManifest(t *testing.T) {
@@ -6992,6 +7020,42 @@
 	})
 }
 
+func TestNoDupeApexFiles(t *testing.T) {
+	android.GroupFixturePreparers(
+		android.PrepareForTestWithAndroidBuildComponents,
+		PrepareForTestWithApexBuildComponents,
+		prepareForTestWithMyapex,
+		prebuilt_etc.PrepareForTestWithPrebuiltEtc,
+	).
+		ExtendWithErrorHandler(android.FixtureExpectsAtLeastOneErrorMatchingPattern("is provided by two different files")).
+		RunTestWithBp(t, `
+			apex {
+				name: "myapex",
+				key: "myapex.key",
+				prebuilts: ["foo", "bar"],
+				updatable: false,
+			}
+
+			apex_key {
+				name: "myapex.key",
+				public_key: "testkey.avbpubkey",
+				private_key: "testkey.pem",
+			}
+
+			prebuilt_etc {
+				name: "foo",
+				src: "myprebuilt",
+				filename_from_src: true,
+			}
+
+			prebuilt_etc {
+				name: "bar",
+				src: "myprebuilt",
+				filename_from_src: true,
+			}
+		`)
+}
+
 func TestRejectNonInstallableJavaLibrary(t *testing.T) {
 	testApexError(t, `"myjar" is not configured to be compiled into dex`, `
 		apex {
diff --git a/apex/bootclasspath_fragment_test.go b/apex/bootclasspath_fragment_test.go
index b298dac..af4fd9f 100644
--- a/apex/bootclasspath_fragment_test.go
+++ b/apex/bootclasspath_fragment_test.go
@@ -71,10 +71,6 @@
 			name: "com.android.art",
 			key: "com.android.art.key",
 			bootclasspath_fragments: ["art-bootclasspath-fragment"],
- 			java_libs: [
-				"baz",
-				"quuz",
-			],
 			updatable: false,
 		}
 
@@ -301,11 +297,7 @@
 				"mybootclasspathfragment",
 			],
 			// bar (like foo) should be transitively included in this apex because it is part of the
-			// mybootclasspathfragment bootclasspath_fragment. However, it is kept here to ensure that the
-			// apex dedups the files correctly.
-			java_libs: [
-				"bar",
-			],
+			// mybootclasspathfragment bootclasspath_fragment.
 			updatable: false,
 		}
 
@@ -445,7 +437,6 @@
 		})
 
 		java.CheckModuleDependencies(t, result.TestContext, "com.android.art", "android_common_com.android.art_image", []string{
-			`bar`,
 			`com.android.art.key`,
 			`mybootclasspathfragment`,
 		})
@@ -559,7 +550,6 @@
 		})
 
 		java.CheckModuleDependencies(t, result.TestContext, "com.android.art", "android_common_com.android.art_image", []string{
-			`bar`,
 			`com.android.art.key`,
 			`mybootclasspathfragment`,
 			`prebuilt_com.android.art`,
@@ -1105,10 +1095,6 @@
 			name: "com.android.art",
 			key: "com.android.art.key",
 			bootclasspath_fragments: ["art-bootclasspath-fragment"],
- 			java_libs: [
-				"baz",
-				"quuz",
-			],
 			updatable: false,
 		}
 
@@ -1270,10 +1256,6 @@
 			name: "com.android.art",
 			key: "com.android.art.key",
 			bootclasspath_fragments: ["art-bootclasspath-fragment"],
- 			java_libs: [
-				"baz",
-				"quuz",
-			],
 			updatable: false,
 		}
 
diff --git a/cc/vndk.go b/cc/vndk.go
index 4cd4d42..6ab4734 100644
--- a/cc/vndk.go
+++ b/cc/vndk.go
@@ -368,7 +368,10 @@
 			}
 			return m.ImageVariation().Variation == android.CoreVariation && lib.shared() && m.IsVndkSp() && !m.IsVndkExt()
 		}
-
+		// VNDK APEX doesn't need stub variants
+		if lib.buildStubs() {
+			return false
+		}
 		useCoreVariant := m.VndkVersion() == mctx.DeviceConfig().PlatformVndkVersion() &&
 			mctx.DeviceConfig().VndkUseCoreVariant() && !m.MustUseVendorVariant()
 		return lib.shared() && m.InVendor() && m.IsVndk() && !m.IsVndkExt() && !useCoreVariant
diff --git a/java/aar.go b/java/aar.go
index 8a83792..ccd68cd 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -525,7 +525,7 @@
 	if sdkDep.hasFrameworkLibs() {
 		a.aapt.deps(ctx, sdkDep)
 	}
-	a.usesLibrary.deps(ctx, sdkDep.hasFrameworkLibs())
+	a.usesLibrary.deps(ctx, false)
 }
 
 func (a *AndroidLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
diff --git a/java/app.go b/java/app.go
index eb1b474..df6698d 100755
--- a/java/app.go
+++ b/java/app.go
@@ -1295,14 +1295,14 @@
 	}
 }
 
-func (u *usesLibrary) deps(ctx android.BottomUpMutatorContext, hasFrameworkLibs bool) {
+func (u *usesLibrary) deps(ctx android.BottomUpMutatorContext, addCompatDeps bool) {
 	if !ctx.Config().UnbundledBuild() || ctx.Config().UnbundledBuildImage() {
 		ctx.AddVariationDependencies(nil, usesLibReqTag, u.usesLibraryProperties.Uses_libs...)
 		ctx.AddVariationDependencies(nil, usesLibOptTag, u.presentOptionalUsesLibs(ctx)...)
-		// Only add these extra dependencies if the module depends on framework libs. This avoids
-		// creating a cyclic dependency:
+		// Only add these extra dependencies if the module is an app that depends on framework
+		// libs. This avoids creating a cyclic dependency:
 		//     e.g. framework-res -> org.apache.http.legacy -> ... -> framework-res.
-		if hasFrameworkLibs {
+		if addCompatDeps {
 			// Dexpreopt needs paths to the dex jars of these libraries in order to construct
 			// class loader context for dex2oat. Add them as a dependency with a special tag.
 			ctx.AddVariationDependencies(nil, usesLibCompat29ReqTag, dexpreopt.CompatUsesLibs29...)
diff --git a/java/droiddoc.go b/java/droiddoc.go
index 8a291ad..aa55f37 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -598,7 +598,7 @@
 	// Droiddoc always gets "-source 1.8" because it doesn't support 1.9 sources.  For modules with 1.9
 	// sources, droiddoc will get sources produced by metalava which will have already stripped out the
 	// 1.9 language features.
-	cmd.FlagWithArg("-source ", "1.8").
+	cmd.FlagWithArg("-source ", getStubsJavaVersion().String()).
 		Flag("-J-Xmx1600m").
 		Flag("-J-XX:-OmitStackTraceInFastThrow").
 		Flag("-XDignore.symbol.file").
diff --git a/java/java.go b/java/java.go
index b3abc91..275abbe 100644
--- a/java/java.go
+++ b/java/java.go
@@ -521,6 +521,11 @@
 	}
 }
 
+// Java version for stubs generation
+func getStubsJavaVersion() javaVersion {
+	return JAVA_VERSION_8
+}
+
 type javaVersion int
 
 const (
@@ -1718,6 +1723,7 @@
 	al.stubsJar = android.PathForModuleOut(ctx, ctx.ModuleName(), "android.jar")
 
 	var flags javaBuilderFlags
+	flags.javaVersion = getStubsJavaVersion()
 	flags.javacFlags = strings.Join(al.properties.Javacflags, " ")
 
 	TransformJavaToClasses(ctx, al.stubsJar, 0, android.Paths{},