Ask for help on code coverage

Hello everyone! Congradulation to Qian Wang & Ralf Jung's excellent work on rust compiler test.

I have read the paper roughly, and have a some question. When I reproducing the code coverage, I always cannot limit the coverage only measured in the /compiler/rustc_mir_transform. How can I do this?

Thanks for your time! Any advice would be helpful for me.

Best regards,
Hang