This is strange, because _execute_child calls os.fsdecode with `args` as the argument, which may be a list. os.fsdecode calls fspath. Now, the python docstring of _fspath, as defined in Lib/os.py on line 1031, clearly states that it will raise a TypeError if the argument is not of type bytes, str or is a os.PathLike object, and that's probably why I wrote the initial code the way I did (catching TypeError from os.fsdecode).

Doesn't the try-except block actually catch this TypeError? I don't understand off the top of my head why my code doesn't catch this exception..