PlayMode tests crash with SIGSEGV (exit code 139) on Unity 6

[CharlieHess]

Bug description

PlayMode tests crash with a native segfault (exit code 139) on Unity 6000.3.8f1 before any test code executes. The crash occurs during the test framework's IPrebuildSetup / BuildActionTaskBase phase. EditMode tests on the same project pass without issue.

Unity version

6000.3.8f1

Runner version

game-ci/unity-test-runner@v4

Runner configuration

• ubuntu-latest
• No custom parameters

Logs

The runner reaches "Testing in playmode", enters PlayMode (GLX context created), then crashes:

# Testing in playmode #
...
UnityEditor.TestTools.TestRunner.TestRun.Tasks.BuildActionTaskBase`1/<ExecuteMethods>d__8<UnityEngine.TestTools.IPrebuildSetup>:MoveNext ()
...
Obtained 49 stack frames.
#5  0x0055bce7673f13 in scripting_method_invoke(...)
#6  0x0055bce764c92c in ScriptingInvocation::Invoke(...)
#7  0x0055bce764ca05 in ScriptingInvocation::Invoke<...>(...)
#8  0x0055bce77ab805 in StackTraceUtilityProxy::ExtractStackTrace(...)
...
#         Failure         #
To find the reason for failure: please search for errors in the log above.
##[error]The process '/usr/bin/docker' failed with exit code 139

Exit code 139 = SIGSEGV. The crash is in the native Unity engine, not in user test code (no TestContext.Progress.WriteLine markers from our tests appear in the output).

Workaround

Run PlayMode tests locally in the editor. Only run EditMode tests in CI.

[CharlieHess]

I've narrowed this down to the code coverage task. The out of the box Linux runner always appends -enableCodeCoverage, and that is exactly what crashes the play mode tests for me. This is the real bug @webbertakken @davidmfinol: #302

[frostebite]

Your own diagnosis in the linked comment (code coverage task is what crashes play mode) matches #302's complaint that there's no way to disable -enableCodeCoverage at all today. Opened #311 to add a coverageEnabled: false opt-out — worth trying once it merges to confirm it resolves this specific SIGSEGV, since it's not yet certain that's the only trigger for this crash on Unity 6000.3.8f1.