TestKit with Spock - Mismatch between directory set in GradleRunner to what the plugin uses

Hi Folks,

We’re using the Gradle 4.8. the development env is MacOS.
We set up the Build result as follows:
BuildResult buildResult = GradleRunner.create()
.withProjectDir(testProjectDir.root)
.withPluginClasspath()
.withArguments(’–debug’, ‘–stacktrace’, ‘–dry-run’, task)
.forwardOutput()
.withDebug(true)
.build()
Where testProjectDir is set in the class as:
@Rule
private final TemporaryFolder testProjectDir = new TemporaryFolder()
When inspecting the value in the test stackframe I see something in the lines of:
/var/folders/ll/5_c9n_mj06l4gkmjwfwmxk080000gp/T/junit6618640855114483875

However on the same run, when putting a breakpoint inside of the plugin itself which is under test, I see the project location as:
/private/var/folders/ll/5_c9n_mj06l4gkmjwfwmxk080000gp/T/junit6618640855114483875

I thought the directory used should be what we specify in the runner. There reason it’s important for us is because as part of the test setup we’re creating a directory under testProjectDir which the plugin needs to interact with.

Any ideas of what I’m missing.

Thanks
-Gabriel