diff --git a/java/bootclasspath.go b/java/bootclasspath.go
index 02833ab..634959a 100644
--- a/java/bootclasspath.go
+++ b/java/bootclasspath.go
@@ -29,7 +29,7 @@
 
 func registerBootclasspathBuildComponents(ctx android.RegistrationContext) {
 	ctx.FinalDepsMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.BottomUp("bootclasspath_deps", bootclasspathDepsMutator)
+		ctx.BottomUp("bootclasspath_deps", bootclasspathDepsMutator).Parallel()
 	})
 }
 
@@ -95,6 +95,15 @@
 	if ctx.OtherModuleDependencyVariantExists(variations, prebuiltName) {
 		ctx.AddVariationDependencies(variations, tag, prebuiltName)
 		addedDep = true
+	} else if ctx.Config().AlwaysUsePrebuiltSdks() && len(variations) > 0 {
+		// TODO(b/179354495): Remove this code path once the Android build has been fully migrated to
+		//  use bootclasspath_fragment properly.
+		// Some prebuilt java_sdk_library modules do not yet have an APEX variations so try and add a
+		// dependency on the non-APEX variant.
+		if ctx.OtherModuleDependencyVariantExists(nil, prebuiltName) {
+			ctx.AddVariationDependencies(nil, tag, prebuiltName)
+			addedDep = true
+		}
 	}
 
 	// If no appropriate variant existing for this, so no dependency could be added, then it is an
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index be202c0..c1068da 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -766,7 +766,7 @@
 			if len(pp) > 0 {
 				updatablePackages = append(updatablePackages, pp...)
 			} else {
-				ctx.ModuleErrorf("Missing permitted_packages")
+				ctx.OtherModuleErrorf(module, "Missing permitted_packages")
 			}
 		}
 	}
diff --git a/java/hiddenapi_modular.go b/java/hiddenapi_modular.go
index 2dceb65..f5afe5d 100644
--- a/java/hiddenapi_modular.go
+++ b/java/hiddenapi_modular.go
@@ -15,6 +15,7 @@
 package java
 
 import (
+	"fmt"
 	"strings"
 
 	"android/soong/android"
@@ -560,7 +561,25 @@
 	for _, module := range contents {
 		bootDexJar := module.bootDexJar()
 		if bootDexJar == nil {
-			ctx.ModuleErrorf("module %s does not provide a dex jar", module)
+			if ctx.Config().AlwaysUsePrebuiltSdks() {
+				// TODO(b/179354495): Remove this work around when it is unnecessary.
+				// Prebuilt modules like framework-wifi do not yet provide dex implementation jars. So,
+				// create a fake one that will cause a build error only if it is used.
+				fake := android.PathForModuleOut(ctx, "fake/boot-dex/%s.jar", module.Name())
+
+				// Create an error rule that pretends to create the output file but will actually fail if it
+				// is run.
+				ctx.Build(pctx, android.BuildParams{
+					Rule:   android.ErrorRule,
+					Output: fake,
+					Args: map[string]string{
+						"error": fmt.Sprintf("missing dependencies: boot dex jar for %s", module),
+					},
+				})
+				bootDexJars = append(bootDexJars, fake)
+			} else {
+				ctx.ModuleErrorf("module %s does not provide a dex jar", module)
+			}
 		} else {
 			bootDexJars = append(bootDexJars, bootDexJar)
 		}
diff --git a/java/platform_bootclasspath.go b/java/platform_bootclasspath.go
index c8fafed..6ebeb6b 100644
--- a/java/platform_bootclasspath.go
+++ b/java/platform_bootclasspath.go
@@ -242,8 +242,15 @@
 		} else {
 			name := ctx.OtherModuleName(m)
 			if apexInfo.IsForPlatform() {
-				// error: this jar is part of the platform
-				ctx.ModuleErrorf("module %q from platform is not allowed in the updatable boot jars list", name)
+				// If AlwaysUsePrebuiltSdks() returns true then it is possible that the updatable list will
+				// include platform variants of a prebuilt module due to workarounds elsewhere. In that case
+				// do not treat this as an error.
+				// TODO(b/179354495): Always treat this as an error when migration to bootclasspath_fragment
+				//  modules is complete.
+				if !ctx.Config().AlwaysUsePrebuiltSdks() {
+					// error: this jar is part of the platform
+					ctx.ModuleErrorf("module %q from platform is not allowed in the updatable boot jars list", name)
+				}
 			} else {
 				// TODO(b/177892522): Treat this as an error.
 				// Cannot do that at the moment because framework-wifi and framework-tethering are in the