Describe the bug
A test suite with no changes has a failing job after upgrading to 7.11.1 ( and still failing on 7.11.3 ). This isn't failing on my local macOS 15.7.1 environment; only on the GitHub runner image below.

Image: ubuntu-24.04
Version: 20251102.99.1
Included Software: https://github.com/actions/runner-images/blob/ubuntu24/20251102.99/images/ubuntu/Ubuntu2404-Readme.md
Image Release: https://github.com/actions/runner-images/releases/tag/ubuntu24%2F20251102.99

To Reproduce

Specific job that fails: See the job at https://github.com/jmertic/lfx-landscape-tools/actions/runs/19296698156/job/55180371131#step:8:58

Answer the questions below:

1. What version of Python are you using? 3.14
2. What version of coverage.py shows the problem? 7.11.1 and later
3. What versions of what packages do you have installed?

• Installing attrs (25.4.0)
• Installing pycparser (2.23)
• Installing rpds-py (0.28.0)
• Installing cffi (2.0.0)
• Installing referencing (0.37.0)
• Installing certifi (2025.11.12)
• Installing charset-normalizer (3.4.4)
• Installing cryptography (46.0.3)
• Installing idna (3.11)
• Installing jsonschema-specifications (2025.9.1)
• Installing typing-extensions (4.15.0)
• Installing urllib3 (2.5.0)
• Installing cattrs (25.3.0)
• Installing click (8.3.0)
• Installing jsonschema (4.25.1)
• Installing packaging (25.0)
• Installing pyjwt (2.10.1)
• Installing pynacl (1.6.1)
• Installing pyproject-hooks (1.2.0)
• Installing platformdirs (4.5.0)
• Installing pyyaml (6.0.3)
• Installing regress (2025.10.1)
• Installing requests (2.32.5)
• Installing ruamel-yaml (0.18.16)
• Installing soupsieve (2.8)
• Installing text-unidecode (1.3)
• Installing url-normalize (2.2.1)
• Installing beautifulsoup4 (4.14.2)
• Installing build (1.3.0)
• Installing check-jsonschema (0.34.1)
• Installing coverage (7.11.1)
• Installing pycairo (1.29.0)
• Installing python-slugify (8.0.4)
• Installing requests-cache (1.2.1)
• Installing pygithub (2.8.1)
• Installing responses (0.25.8)
• Installing validators (0.35.0)

1. What code shows the problem? Test code is at https://github.com/jmertic/lfx-landscape-tools/blob/219691aad65fc6902a31aabe2f576a066d9e9c81/test/test_landscapeoutput.py#L191
2. What commands should we run to reproduce the problem? Job at https://github.com/jmertic/lfx-landscape-tools/actions/runs/19296698156/workflow#L41

Expected behavior
The tests should all pass, like they did for 7.11.0 and earlier.

Additional context
I cannot reproduce this on my local macOS 15.7.1 / Python 3.14 install; only the GitHub runner shows the error.

Further, if I pin coverage to 7.11.0, the error goes away

Thank you all!