When importing an ant build.xml, I get a ConcurrentModificationException

Old Forum Archive
1

Hi Guys,

I am looking to move our existing ant infrastructure to Gradle progressively. As such, I am importing an ant build and just trying to run the ant tasks from gradle.

Our build environment uses Ivy and Ant.

The setup is a basic build.xml that imports a large build-common-ant.xml that imports a large build-common-ivy.xml. Most of the tasks work, however, every now and again I hit a ConcurrentModificationException.

It sometimes gets resolved by specifying the and target to as build-common.export instead of just export.I haven’t been able to assemble a small example that exhibits this behavior yet.

Here’s the stack trace:

* Exception is:
java.util.ConcurrentModificationException
        at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.removeShouldRunAfterSuccessorsIfTheyImposeACycle(DefaultTaskExecutionPlan.java:298)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.determineExecutionPlan(DefaultTaskExecutionPlan.java:223)
        at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.ensurePopulated(DefaultTaskGraphExecuter.java:150)
        at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:84)
        at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:29)
        at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
        at org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExecuter.java:23)
        at org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecuter.java:68)
        at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
        at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
        at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:55)
        at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:149)
        at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:106)
        at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:86)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:80)
        at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:33)
        at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:24)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:36)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:26)
        at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:51)
        at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:171)
        at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:237)
        at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:210)
        at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:35)
        at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:24)
        at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:206)
        at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:169)
        at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)
        at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)
        at org.gradle.launcher.Main.doAction(Main.java:33)
        at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)
        at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:54)
        at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:35)
        at org.gradle.launcher.GradleMain.main(GradleMain.java:23)

I am running the latest 2.1 release of Gradle.

If someone can point me in the right direction to investigate?

Thanks, Marc

2

Hello Marc,

thanks for reporting this. It would be really helpful to get a reproducable example working that lets us dig deeper into this. I raised GRADLE-3166 to track this issue in the gradle issue tracker.

3

Hi Rene,

Thanks for the quick reply. I was able to find a relatively simple item that fails as well.

I’ve posted 4 files here: https://gist.github.com/anonymous/6a3660c787319ccb285b#file-build-gradle

Broken from Gradle:

$ gradle service-version
:build-number
  FAILURE: Build failed with an exception.
  * What went wrong:
java.util.ConcurrentModificationException (no error message)
  * Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  BUILD FAILED
  Total time: 1.604 secs
$

Working from ANT:

$ ant service-version
Buildfile: /home/mrawji/workspaces/gradle/broken/build.xml
  init:
  resolve:
  build-number:
  service-version:
  BUILD SUCCESSFUL
Total time: 0 seconds
$

If the build-common-ant-ivy.xml has the part of it commented out (see comments in the file)

$ gradle service-version
:build-number
:init
:resolve
:build-number
:service-version
  BUILD SUCCESSFUL
  Total time: 1.653 secs
$
4

Thanks for the instructions to reproduce. I’ve added this to the schedule to look at before the release of 2.2.

5

If it helps in any way, this problem seem to happen starting from 1.12. Works fine since 1.11. Although, 1.11 is broken for ant target dependency resolution.

6

I am trying to do the same, but not getting java.util.ConcurrentModificationException. In my case, Gradle can not load the Ivy library. In this case, where is Ivy library located?