Coverage Fails due to fs call intercepts on 3.14

[cjames23]

Describe the bug

In 3.14 with coverage pyfakefs intercepts file system calls leading to coverage throwing an error for NoSource. This is likely due to changes in coverage with 3.14 using sys.monitoring instead of sys.settrace() is what I have narrowed it down to.

How To Reproduce

Run unit tests that use pyfakefs with coverage[toml] with 3.14 using pytest 9.0.0 and when coverage tries to access the file system for branch coverage this will be triggered.

Example test failure in hatch https://github.com/pypa/hatch/actions/runs/19286882217/job/55149434317

Your environment
Please run the following in the environment where the problem happened and
paste the output.

python -c "import platform; print(platform.platform())"
python -c "import sys; print('Python', sys.version)"
python -c "from pyfakefs import __version__; print('pyfakefs', __version__)"
python -c "import pytest; print('pytest', pytest.__version__)"

See link to Github Workflow for Tests in hatch.

[mrbean-bremen]

Thanks - I will have a look tonight (hopefully).

[mrbean-bremen]

I could reproduce the problem with your project (using the respective branch before pyfakefs has been removed), but didn't get far yet. It looks like I will not be able to tackle this before the weekend.
I guess that you don't need an urgent fix, as you have removed pyfakefs from the tests at all (well, the only test where it was used).

[cjames23]

Correct, this is not urgent on our end and was more to make sure it was documented.