x/mobile: Gradle version > 3.5.1 produces NullPointerException in GobindPlugin #21594

mtw-g · 2017-08-24T16:55:22Z

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (`go version`)?

1.8

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (`go env`)?

linux (Ubuntu) / amd64

What did you do?

Android Studio 3.0 forced an update to Gradle plugin from 3.5.1 to 4.1x.

If possible, provide a recipe for reproducing the error.

Create an Android Studio project and add a module that uses the Gobind plugin (version 0.2.9)

Attempt to build the project

What did you expect to see?

Android Studio / Gradle should build an .aar from the Go source.

What did you see instead?

The plugin produces the following stacktrace:

FAILURE: Build failed with an exception.

What went wrong:
Execution failed for task ':agent:gobind'.
> Cannot get property 'classpath' on null object

* Try:
Run with --info or --debug option to get more log output.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':agent:gobind'.
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:100)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:70)
at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:63)
at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:88)
at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:52)
at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:248)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:197)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:107)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:241)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:230)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.processTask(DefaultTaskPlanExecutor.java:124)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.access$200(DefaultTaskPlanExecutor.java:80)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:105)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:99)
at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:625)
at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:580)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:99)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
Caused by: java.lang.NullPointerException: Cannot get property 'classpath' on null object
at org.golang.mobile.GomobileTask.gomobile(GobindPlugin.groovy:219)
at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.doExecute(DefaultTaskClassInfoStore.java:141)
at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:134)
at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:121)
at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:731)
at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:705)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:122)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:197)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:107)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:111)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:92)
... 27 more

The text was updated successfully, but these errors were encountered:

hyangah · 2017-08-24T17:03:36Z

I am a bit puzzled by the line numbers in the NullPointerException (GobindPlugin.groovy:219).
I assume the plugin worked before Android Studio upgrade.

mtw-g · 2017-08-24T17:16:05Z

That's almost correct - the plugin was working on Android Studio 3.0. What caused the breakage was being forced to update the Gradle version from 3.5.1 to 4.1.x

Qheb · 2017-09-22T09:46:34Z

Hello,

I am stuck on the same issue (NullPointerException at GobindPlugin.groovy:219), and this doesn't seem to be related with the Gradle version (I am reproducing it with Gradle 3.5).

What feels really strange is that I am using the gomobile plugin v0.2.9 and this is supposed to be fixed by @eliasnaur in this commit.
Moreover, I don't see how there could be any NullPointerException at line 219 in the current code:

if (javaCompile) { // <- This is line 219
    def classpath = project.files(javaCompile.classpath, javaCompile.destinationDir)
    cmd << "-classpath"
    cmd << classpath.join(File.pathSeparator)
}

Out of curiosity, I opened and decompiled my gobindPlugin-0.2.9.jar, and here is what I found:

Object classpath = var1[1].call(var1[2].callGroovyObjectGetProperty(this), var1[3].callGetProperty(this.javaCompile), var1[4].callGetProperty(this.javaCompile));
var1[5].call(cmd, "-classpath");
var1[6].call(cmd, var1[7].call(classpath, var1[8].callGetProperty(File.class)));
var1[9].call(cmd, "-o");
var1[10].call(cmd, var1[11].call(this.outputFile));
var1[12].call(cmd, "-target");

This really looks like the groovy code before the fix...

According to the history the 0.2.9 version is supposed to include the fix. But is there any possibility that the wrong source code version was shipped and tagged as 0.2.9 ?

eliasnaur · 2017-09-22T11:09:34Z

/CC @hyangah

charlescui · 2017-10-28T16:21:46Z

same problem

gradle -v

------------------------------------------------------------
Gradle 2.14-rc-5
------------------------------------------------------------

Build time:   2016-06-07 13:58:17 UTC
Revision:     660f0c5357f2889208c85d20614904b397dfd47b

Groovy:       2.4.4
Ant:          Apache Ant(TM) version 1.9.6 compiled on June 29 2015
JVM:          1.8.0_112 (Oracle Corporation 25.112-b16)
OS:           Mac OS X 10.12.5 x86_64

Erro info:

Error:Execution failed for task ':server:gobind'.
> Cannot get property 'classpath' on null object

daudrain · 2017-11-04T22:24:38Z

Same problem

------------------------------------------------------------
Gradle 2.10
------------------------------------------------------------

Build time:   2015-12-21 21:15:04 UTC
Build number: none
Revision:     276bdcded730f53aa8c11b479986aafa58e124a6

Groovy:       2.4.4
Ant:          Apache Ant(TM) version 1.9.3 compiled on December 23 2013
JVM:          1.8.0_131 (Oracle Corporation 25.131-b11)
OS:           Mac OS X 10.12.6 x86_64

18:16:37.296 [ERROR] [org.gradle.BuildExceptionReporter] Caused by: java.lang.NullPointerException: Cannot get property 'classpath' on null object
18:16:37.297 [ERROR] [org.gradle.BuildExceptionReporter] 	at org.golang.mobile.GomobileTask.gomobile(GobindPlugin.groovy:219)
18:16:37.297 [ERROR] [org.gradle.BuildExceptionReporter] 	at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:75)

daudrain · 2017-11-04T22:48:58Z

I've copied the plugin source to buildSrc directory of the Android bind example
cp -R misc/androidstudio/src/main example/bind/android/buildSrc/src/main

And the build succeeded.
As suggested by @Qheb , the published plugin may not contain the fix.

jeffallen · 2017-12-22T09:50:11Z

Hello @hyangah, this issue is making it impossible to build gomobile apps out of the box, which is pretty problematic... I was trying to sell some coworkers on gomobile, and the result was instead, "sorry, it seems like gomobile is not working and/or not supported right now".

CC @broady who might be able to find the right person for this after vacation.

seebs · 2017-12-29T21:46:36Z

Confirming that the plugin source copy fix worked. To be specific, copying from golang.org/x/mobile/misc/androidstudio/src/main to golang.org/x/mobile/example/bind/android/buildSrc/src/main. Also had to remove the existing plugin line specifying the gobind plugin, and add a new line, outside the plugins section, reading "apply plugin: 'org.golang.mobile.bind'".

Which got me to lint failures, papered over by adding the suggested don't-abort-on-failure stanza to app/build.gradle. (Does not work in build.gradle or hello/build.gradle.) And with that, I was able to get the thing to compile. Yayyy.

rsc · 2018-01-08T20:37:01Z

@jeffallen:

"sorry, it seems like gomobile is not working and/or not supported right now".

That's correct. As it says in golang.org/x/mobile/README, "The Go Mobile project is experimental. Use this at your own risk. While we are working hard to improve it, neither Google nor the Go team can provide end-user support." You have probably also noticed that there's very little activity in this repo recently from people at Google. We are focused on other things, although we're very grateful for the community work that has gone into keeping x/mobile working as we've stepped back, especially from @eliasnaur. While working on the compilers and standard library, we do continue to pay attention to keeping the mobile builders happy.

If there's some approval or something needed here, we can easily do that. It looks instead to me like code changes are needed but not yet written. CLs are welcome, but those of us at Google are not likely to get to this specific issue ourselves.

Thanks.

jeffallen · 2018-01-08T20:53:41Z

@Qheb commented on 22 Sep 2017 that the plugin pushed to the distribution website does not match the code pushed to git. That is the correct diagnosis, and now what we need is someone from the Go team with the rights to push a new copy of the plugin to do that.

hyangah · 2018-01-08T20:56:18Z

I am working on it to push but I am struggling with verifying the newly built plugin working with the newly installed android studio. Can anyone check if https://plugins.gradle.org/plugin/org.golang.mobile.bind.canary is working?

hyangah · 2018-01-08T21:28:15Z

The latest error I got after updating the golang.org/x/mobile/example/bind/android

use the updated gradle (classpath 'com.android.tools.build:gradle:3.0.1' in build.gradle
hello/build.gradle to point to "org.golang.mobile.bind.canary" version "0.2.9.rc1"

Unable to resolve dependency for ':app@debug/compileClasspath': Failed to transform file 'hello.aar' to match attributes {artifactType=android-exploded-aar} using transform ExtractAarTransform

Failed to transform file 'hello.aar' to match attributes {artifactType=android-exploded-aar} using transform ExtractAarTransform
 > java.io.FileNotFoundException: /usr/local/google/home/hakim/go/src/golang.org/x/mobile/example/bind/android/hello/hello.aar (No such file or directory)
    > /usr/local/google/home/hakim/go/src/golang.org/x/mobile/example/bind/android/hello/hello.aar (No such file or directory)

The aar file the gobindplugin explects is not there.

hyangah · 2018-01-08T22:18:27Z

Even though Android Studio is complaining about gradle project sync failure, build seems to be working. So I will just push it as 0.2.10 and hope the gradle sync failure warning issue seperately.

Many little bits in the bind example are outdated and need to be updated. I will file bugs for records. We need help to update the examples and the plugin code.

gopherbot · 2018-01-08T22:33:16Z

Change https://golang.org/cl/86775 mentions this issue: misc/androidstudio: update to 0.2.10

gopherbot · 2018-01-08T23:16:36Z

Change https://golang.org/cl/86795 mentions this issue: example: update android examples to use 0.2.10 plugin

jeffallen · 2018-01-09T08:52:43Z

In addition to changing the Go plugin to 0.2.10, I found that I needed to downgrade gradle to 2.10 to make it work, because of this error: https://stackoverflow.com/questions/37655814/gradle-sync-failed-unable-to-find-method

0.2.9 was broken - for unknown reasons, the plugin was built on top of stale sources. Updates golang/go#21594 Plugin 0.2.10 was built with rev 50b7067 and this change. % docker run --rm -u root -v "$PWD":/home/gradle/project \ -w /home/gradle/project gradle:latest \ gradle publishPlugins Gradle version is 4.0.1. Change-Id: I146dc67cbad3c9945a2acdf4ac7993283725090a Reviewed-on: https://go-review.googlesource.com/86775 Reviewed-by: Elias Naur <elias.naur@gmail.com>

Also, modernize the build.gradle configurations to work with recent Android plugin (>=3.0.0) https://developer.android.com/studio/build/gradle-plugin-3-0-0-migration.html Update golang/go#21594 Change-Id: Ic2162db7367b60ad873149ab62767f36481fa80f Reviewed-on: https://go-review.googlesource.com/86795 Reviewed-by: Elias Naur <elias.naur@gmail.com>

eliasnaur · 2018-03-14T22:39:39Z

Is this still a problem with the plugin version 0.2.10? If not, please close this issue.

eliasnaur · 2019-03-08T22:22:52Z

The plugin is gone from gomobile.

bradfitz changed the title ~~Gradle version > 3.5.1 produces NullPointerException in GobindPlugin~~ x/mobile: Gradle version > 3.5.1 produces NullPointerException in GobindPlugin Nov 4, 2017

gopherbot added this to the Unreleased milestone Nov 4, 2017

gopherbot added the mobile Android, iOS, and x/mobile label Nov 4, 2017

jeffallen mentioned this issue Dec 22, 2017

gradlew not found mpl/go4droid#1

Closed

mpl mentioned this issue Dec 22, 2017

./gradlew assembleDebug fails mpl/go4droid#2

Closed

seebs mentioned this issue Dec 29, 2017

x/mobile/app/ivy/android: no documentation #23285

Closed

eliasnaur closed this as completed Mar 8, 2019

golang locked and limited conversation to collaborators Mar 7, 2020

gopherbot added the FrozenDueToAge label Mar 7, 2020

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x/mobile: Gradle version > 3.5.1 produces NullPointerException in GobindPlugin #21594

x/mobile: Gradle version > 3.5.1 produces NullPointerException in GobindPlugin #21594

mtw-g commented Aug 24, 2017

hyangah commented Aug 24, 2017

mtw-g commented Aug 24, 2017

Qheb commented Sep 22, 2017

eliasnaur commented Sep 22, 2017

charlescui commented Oct 28, 2017 •

edited

daudrain commented Nov 4, 2017

daudrain commented Nov 4, 2017 •

edited

jeffallen commented Dec 22, 2017

seebs commented Dec 29, 2017

rsc commented Jan 8, 2018

jeffallen commented Jan 8, 2018

hyangah commented Jan 8, 2018

hyangah commented Jan 8, 2018

hyangah commented Jan 8, 2018

gopherbot commented Jan 8, 2018

gopherbot commented Jan 8, 2018

jeffallen commented Jan 9, 2018 •

edited

eliasnaur commented Mar 14, 2018

eliasnaur commented Mar 8, 2019

x/mobile: Gradle version > 3.5.1 produces NullPointerException in GobindPlugin #21594

x/mobile: Gradle version > 3.5.1 produces NullPointerException in GobindPlugin #21594

Comments

mtw-g commented Aug 24, 2017

What version of Go are you using (go version)?

Does this issue reproduce with the latest release?

What operating system and processor architecture are you using (go env)?

What did you do?

If possible, provide a recipe for reproducing the error.

What did you expect to see?

What did you see instead?

hyangah commented Aug 24, 2017

mtw-g commented Aug 24, 2017

Qheb commented Sep 22, 2017

eliasnaur commented Sep 22, 2017

charlescui commented Oct 28, 2017 • edited

daudrain commented Nov 4, 2017

daudrain commented Nov 4, 2017 • edited

jeffallen commented Dec 22, 2017

seebs commented Dec 29, 2017

rsc commented Jan 8, 2018

jeffallen commented Jan 8, 2018

hyangah commented Jan 8, 2018

hyangah commented Jan 8, 2018

hyangah commented Jan 8, 2018

gopherbot commented Jan 8, 2018

gopherbot commented Jan 8, 2018

jeffallen commented Jan 9, 2018 • edited

eliasnaur commented Mar 14, 2018

eliasnaur commented Mar 8, 2019

What version of Go are you using (`go version`)?

What operating system and processor architecture are you using (`go env`)?

charlescui commented Oct 28, 2017 •

edited

daudrain commented Nov 4, 2017 •

edited

jeffallen commented Jan 9, 2018 •

edited