Debugging "Unknown Source" and "Unsupported evaluation in unmanaged classpath entry"

[PhilDakin]

When running test suites from spark-rapids, Metals is unable to resolve my source files with the following error:

If I evaluate local variables in the stack frame, it works fine. But if I try to access e.g. a test suite class definition, I see the following error:

2023.10.31 00:46:31 ERROR [error response][evaluate]: Cannot evaluate because of java.lang.Exception: Unsupported evaluation in unmanaged classpath entry: /home/ec2-user/my-spark-rapids/spark-rapids/tests/target/spark311/test-classes.

Per the Scala documentation, "Unmanaged files are manually created files that are outside of the control of the build." I am surprised to see /home/ec2-user/my-spark-rapids/spark-rapids/tests/target/spark311/test-classes listed as unmanaged, because it is definitely an artifact created when the module is built.

What would you recommend for continued debugging of this issue? Since spark-rapids is using mvn and not sbt, it isn't clear to me how the unmanaged/managed concept from the SBT docs applies here.