Don't use default interface method bytecode optimization for target 1.8

android/build.gradle

@@ -151,7 +151,8 @@ subprojects {
 
         if (isKotlinLibrary) {
             def extraCompilerArgs = [
-                    "-Xjvm-default=all"
+                    // See https://github.com/bazelbuild/bazel/issues/15144
+                    "-Xjvm-default=enable"
             ]
             if (project.name in moduleFriends.keySet()) {
                 def friendName = moduleFriends[project.name]

android/libraries/rib-android-core/src/main/kotlin/com/uber/rib/core/ActivityDelegate.kt

@@ -27,24 +27,31 @@ import androidx.annotation.IntRange
  */
 interface ActivityDelegate {
   /** @see [Activity.onCreate] */
+  @JvmDefault
   fun onCreate(savedInstanceState: Bundle?) {}
 
   /** @see [Activity.onStart] */
+  @JvmDefault
   fun onStart() {}
 
   /** @see [Activity.onResume] */
+  @JvmDefault
   fun onResume() {}
 
   /** @see [Activity.onPause] */
+  @JvmDefault
   fun onPause() {}
 
   /** @see [Activity.onStop] */
+  @JvmDefault
   fun onStop() {}
 
   /** @see [Activity.onDestroy] */
+  @JvmDefault
   fun onDestroy() {}
 
   /** @see [Activity.onActivityResult] */
+  @JvmDefault
   fun onActivityResult(
     activity: Activity,
     requestCode: Int,
@@ -53,6 +60,7 @@ interface ActivityDelegate {
   ) {}
 
   /** @see [Activity.onRequestPermissionsResult] */
+  @JvmDefault
   fun onRequestPermissionsResult(
     activity: Activity,
     @IntRange(from = 0, to = 255) requestCode: Int,

android/libraries/rib-android/src/main/kotlin/com/uber/rib/core/RxActivityEvents.kt

@@ -32,6 +32,7 @@ interface RxActivityEvents {
    * @param clazz The [ActivityLifecycleEvent] subclass you want.
    * @return an observable of this activity's lifecycle events.
    */
+  @JvmDefault
   fun <T : ActivityLifecycleEvent> lifecycle(clazz: Class<T>): Observable<T> {
     return lifecycle()
       .filter { activityEvent -> clazz.isAssignableFrom(activityEvent.javaClass) }
@@ -43,6 +44,7 @@ interface RxActivityEvents {
    * @param clazz The [ActivityCallbackEvent] subclass you want.
    * @return an observable of this activity's callbacks events.
    */
+  @JvmDefault
   fun <T : ActivityCallbackEvent> callbacks(clazz: Class<T>): Observable<T> {
     return callbacks()
       .filter { activityEvent -> clazz.isAssignableFrom(activityEvent.javaClass) }

android/libraries/rib-base/src/main/kotlin/com/uber/rib/core/Worker.kt

@@ -27,8 +27,10 @@ interface Worker {
    *
    * @param lifecycle The lifecycle of the worker to use for subscriptions.
    */
+  @JvmDefault
   fun onStart(lifecycle: WorkerScopeProvider) {}
 
   /** Called when the worker is stopped.  */
+  @JvmDefault
   fun onStop() {}
 }