mock uid and gid not working as expected

[arch-mage]

I'm writing a test suite to test my script that modify some directory. My test expecting failure if executed
without permission. Here, it mocks a directory to be owned by root. But, my script (which it task is move the directory) can still move that directory.

[stelcheck]

I am having a similar issue with file permissions. I can also delete a file with permissions set to 0444.