Issues matcher file name challenge

I am running an external build tool as part of my build process. One problem I have is that because of subdirectories (sub projects), the path emitted by the compiler might not include my project prefix.

I can figure out the prefix before running the command, but I don’t see a way to influence the issue parser, with the possible exception of using a separate external program (shell script I guess) to parse the output and prepend the path prefix when needed.

Is there a better way to achieve this?

Also, I would like as part of the Tasks API to be be able to flag a successful Run in the same way we do for a Build task. (Meaning I can see the success indicators rather than just a silent error – I do this for running unit tests.)