[BUG] Puzzling coverage computation?

Describe the bug

I'm not sure if this is a bug in codecov-action, https://github.com/getsentry/prevent-cli (formerly codecov-cli), or my own (mis)understanding of how the wholle coverage collection process works (highly possible), but I am getting a rather strange code coverage report for a project that I'm working on. The coverage in question can be found on:

https://app.codecov.io/gh/neuronsimulator/nrn/commit/c81be96caac3712c53784a1597f56062f0747854/blob/share/lib/python/neuron/nmodl/ode.py?dropdown=coverage#L132

As you see, the coverage is somewhat nonsensical:

as it basically skips over lines that should always run.

To Reproduce

Not sure what is the exact source of the problem.

Expected behavior

The coverage report should include basically all of the lines in the screenshot above.

Regression

Not sure since we didn't cover this file before (i.e. it had 0% coverage).

Screenshots

See above.

Versions

• OS: Linux
• Git Host: GitHub
• CI/CD: GHA (ubuntu-22.04 host)
• Uploader: codecov/codecov-action@v4, codecov-cli cli-11.0.3 (according to the logs, see below)

Commit and CI link

CI logs are here:

https://github.com/neuronsimulator/nrn/actions/runs/16566967873/job/46849303386?pr=3544#step:26:1

Additional context

Bumped into this behavior while working on https://github.com/neuronsimulator/nrn/pull/3544

Start by reviewing the Codecov report for share/lib/python/neuron/nmodl/ode.py and the linked GitHub Actions logs from codecov-action@v4 using codecov-cli 11.0.3. Compare the reported coverage with the lines shown in the issue, then determine whether the behavior originates in the action, CLI, or project coverage data. Done means a reproducible diagnosis and a clearly identified component or configuration needing correction.