Build fails with with error "Process 'Gradle Test Executor' finished with non-zero exit value 255"

[Kira Resari]

Ever since Friday, our builds have been failing on Bamboo with the following error:

24-Apr-2020 12:28:33 FAILURE: Build failed with an exception.
24-Apr-2020 12:28:33 
24-Apr-2020 12:28:33 * What went wrong:
24-Apr-2020 12:28:33 Execution failed for task ':knight:test'.
24-Apr-2020 12:28:33 > Process 'Gradle Test Executor 2' finished with non-zero exit value 255
24-Apr-2020 12:28:33 This problem might be caused by incorrect test process configuration.
24-Apr-2020 12:28:33 Please refer to the test execution section in the User Manual at https://docs.gradle.org/6.1.1/userguide/java_testing.html#sec:test_execution
24-Apr-2020 12:28:33 
24-Apr-2020 12:28:33 * Try:
24-Apr-2020 12:28:33 Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
24-Apr-2020 12:28:33 
24-Apr-2020 12:28:33 * Get more help at https://help.gradle.org

However, absolutely nothing changed in the project since then. Running a build that passed before now fails. How can this happen?

Our only guess at this point is that something went wrong with the Bamboo configuration. We did some changes on Friday, including switching some projects to JDK 11, but reverted them after some branches started failing.

One branch still works, but we can't figure out what's different. We already tried switching the JDK versions back and forth, but so far without any success.

Could something external have changed then? In our build.gradle we use only versioned dependencies, so I don't think that could be the issue. But at this point, I don't really have any ideas what could be going wrong.

Any ideas or help would be greatly appreciated.

[Kira Resari · Accepted solution]

We managed to get it to work again by changing the actual build step from:

./gradlew clean build -d

To:

./gradlew clean build -d
./gradlew --stop

However, this still does not explain why it was working up until Friday. Any ideas?