Problem with java testfixtures and custom source path

[jpwilhelms]

Importing a gradle project into eclipse yields an error when using a custom source path for testfixture sources/resources.

Expected Behavior

The import should work without any failure.

Current Behavior

Eclipse shows 1 Error: "Failed to configure project buildship-test"

Java Model Exception: Java Model Status [Test source folder 'xtestx' in project 'buildship-test' must have an output folder that is not also used for main sources]
	at org.eclipse.jdt.internal.core.JavaModelOperation.runOperation(JavaModelOperation.java:802)
	at org.eclipse.jdt.internal.core.JavaProject.setRawClasspath(JavaProject.java:3656)
	at org.eclipse.jdt.internal.core.JavaProject.setRawClasspath(JavaProject.java:3616)
	at org.eclipse.jdt.internal.core.JavaProject.setRawClasspath(JavaProject.java:3672)
	at org.eclipse.buildship.core.internal.workspace.SourceFolderUpdater.updateSourceFolders(SourceFolderUpdater.java:71)
	at org.eclipse.buildship.core.internal.workspace.SourceFolderUpdater.update(SourceFolderUpdater.java:169)
	at org.eclipse.buildship.core.internal.workspace.BaseConfigurator.synchronizeJavaProjectInTransaction(BaseConfigurator.java:116)
	at org.eclipse.buildship.core.internal.workspace.BaseConfigurator.access$000(BaseConfigurator.java:40)
	at org.eclipse.buildship.core.internal.workspace.BaseConfigurator$1.run(BaseConfigurator.java:105)
	at org.eclipse.jdt.internal.core.BatchOperation.executeOperation(BatchOperation.java:41)
	at org.eclipse.jdt.internal.core.JavaModelOperation.run(JavaModelOperation.java:740)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2313)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2338)
	at org.eclipse.jdt.core.JavaCore.run(JavaCore.java:5917)
	at org.eclipse.jdt.core.JavaCore.run(JavaCore.java:5874)
	at org.eclipse.buildship.core.internal.workspace.BaseConfigurator.synchronizeJavaProject(BaseConfigurator.java:101)
	at org.eclipse.buildship.core.internal.workspace.BaseConfigurator.configure(BaseConfigurator.java:91)
	at org.eclipse.buildship.core.internal.workspace.BaseConfigurator.configure(BaseConfigurator.java:66)
	at org.eclipse.buildship.core.internal.extension.InternalProjectConfigurator.configure(InternalProjectConfigurator.java:65)
	at org.eclipse.buildship.core.internal.workspace.ProjectConfigurators.configureConfigurators(ProjectConfigurators.java:70)
	at org.eclipse.buildship.core.internal.workspace.SynchronizeGradleBuildOperation.synchronizeOpenWorkspaceProject(SynchronizeGradleBuildOperation.java:163)
	at org.eclipse.buildship.core.internal.workspace.SynchronizeGradleBuildOperation.synchronizeWorkspaceProject(SynchronizeGradleBuildOperation.java:137)
	at org.eclipse.buildship.core.internal.workspace.SynchronizeGradleBuildOperation.synchronizeGradleProjectWithWorkspaceProject(SynchronizeGradleBuildOperation.java:127)
	at org.eclipse.buildship.core.internal.workspace.SynchronizeGradleBuildOperation.access$000(SynchronizeGradleBuildOperation.java:42)
	at org.eclipse.buildship.core.internal.workspace.SynchronizeGradleBuildOperation$1.run(SynchronizeGradleBuildOperation.java:85)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2313)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2333)
	at org.eclipse.buildship.core.internal.workspace.SynchronizeGradleBuildOperation.synchronizeProjectsWithWorkspace(SynchronizeGradleBuildOperation.java:82)
	at org.eclipse.buildship.core.internal.workspace.SynchronizeGradleBuildOperation.run(SynchronizeGradleBuildOperation.java:64)
	at org.eclipse.buildship.core.internal.DefaultGradleBuild$SynchronizeOperation.runInToolingApi(DefaultGradleBuild.java:230)
	at org.eclipse.buildship.core.internal.operation.DefaultToolingApiOperationManager$WorkspaceRunnableAdapter.run(DefaultToolingApiOperationManager.java:58)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2313)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2338)
	at org.eclipse.buildship.core.internal.operation.DefaultToolingApiOperationManager.run(DefaultToolingApiOperationManager.java:39)
	at org.eclipse.buildship.core.internal.DefaultGradleBuild$SynchronizeOperation.run(DefaultGradleBuild.java:192)
	at org.eclipse.buildship.core.internal.DefaultGradleBuild.synchronize(DefaultGradleBuild.java:100)
	at org.eclipse.buildship.core.internal.workspace.SynchronizationJob.runInToolingApi(SynchronizationJob.java:64)
	at org.eclipse.buildship.core.internal.workspace.SynchronizationJob.runInToolingApi(SynchronizationJob.java:30)
	at org.eclipse.buildship.core.internal.operation.ToolingApiJob$1.runInToolingApi(ToolingApiJob.java:54)
	at org.eclipse.buildship.core.internal.operation.DefaultToolingApiOperationManager$WorkspaceRunnableAdapter.run(DefaultToolingApiOperationManager.java:58)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2313)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2338)
	at org.eclipse.buildship.core.internal.operation.DefaultToolingApiOperationManager.run(DefaultToolingApiOperationManager.java:39)
	at org.eclipse.buildship.core.internal.operation.ToolingApiJob.run(ToolingApiJob.java:65)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)

Context

I try to migrate a large and complex project from ant to gradle. With ant, we have build a custom .classpath file for eclipse so that all sources and resources of type 'test' and 'testfixtures' are handled identically. I already switched the project to gradle, but we still use our custom .classpath file due to this error in buildship/eclipse.

Steps to Reproduce

I have created a really simple project to reproduce this behaviour: github You can easily switch between working and not working by changing the source path from something containing the string 'test' to something not containing the string 'test'.

Your Environment

• Eclipse 2021-09
• buildship 3.1.5.v20210113-0929
• gradle 7.2
• Windows Server 2019