Plugin fails on Android project when Gradle Instant Execution is enabled

[eskatos]

Run a build on an android project that uses the protobug plugin with -Dorg.gradle.unsafe.instant-execution=true, it fails with the following report:

▼ task:subproject:generateDebugProto:clipboard: of type com.google.protobuf.gradle.GenerateProtoTask:clipboard:
 ▼ fieldactions:clipboard: of com.google.protobuf.gradle.GenerateProtoTask:clipboard:
  ▼ bean of type org.gradle.api.internal.AbstractTask$ClosureTaskAction:clipboard:
   ▼ fieldclosure:clipboard: of org.gradle.api.internal.AbstractTask$ClosureTaskAction:clipboard:
    ▼ bean of type com.google.protobuf.gradle.ToolsLocator$_registerDependencyWithTasks_closure2:clipboard:
     ▼ fielddep:clipboard: of com.google.protobuf.gradle.ToolsLocator$_registerDependencyWithTasks_closure2:clipboard:
      ▼ bean of type groovy.lang.Reference:clipboard:
       ▼ fieldvalue:clipboard: of groovy.lang.Reference:clipboard:
        ▼ bean of type org.gradle.api.internal.artifacts.dependencies.DefaultExternalModuleDependency:clipboard:
         ▼ fieldattributesFactory:clipboard: of org.gradle.api.internal.artifacts.dependencies.DefaultExternalModuleDependency:clipboard:
          ▼ bean of type org.gradle.api.internal.attributes.DefaultImmutableAttributesFactory:clipboard:
           ▼ fieldisolatableFactory:clipboard: of org.gradle.api.internal.attributes.DefaultImmutableAttributesFactory:clipboard:
            ▼ bean of type org.gradle.internal.snapshot.impl.DefaultValueSnapshotter

#381 fixed the plugin for Java/Kotlin only builds but there are more issues with Android builds.

[ejona86]

That doesn't actually include any error. What is it saying is wrong?

[eskatos]

Sorry my report wasn't clear. I'll try to clarify.

I just tried to run ProtobufAndroidPluginTest using latest Gradle nightly (6.5-20200415221304+0000) and latest AGP alpha (4.1.0-alpha05) with instant execution enabled and here is the report I get:

You can download and look at the report instant-execution-report.zip

The problems under Gradle runtime are from AGP itself and should be fixed soon.

Instant execution serializes and reuses the Gradle task graph. The two problems reported for the GenerateProtoTask points at state held by the task instances that are not supported by instant execution: SourceSet instances, and AGP Variant instances.

In order to fix the protobuf plugin so it supports instant execution on Android builds it needs to be reworked so that GenerateProtoTask doesn't hold references to those instances.

[voidzcy]

The original issue should have been fixed by #408. The remaining problems with configuration cache (instant execution) are tracked by #409 and #419. So, closing this one.