[SciPy-Dev] Measuring test coverage of a Cython module

[Lars G.]

Hi,
I'm trying to measure the test coverage of a Cython module. However the
module in question (`scipy/signal/peak_finding_utils.pyx`) doesn't show
up in the final report.

What I have tried so far:

1. Added `plugins = Cython.coverage` to the `.coveragerc` file.

2. Added
# cython: linetrace=True
# distutils: define_macros=CYTHON_TRACE_NOGIL=1
to the header of `peak_finding_utils.pyx`

3. Build binaries inplace with
$ python setup.py build_ext --inplace

4. Measured test coverage
a) with `runtests.py`
$ python runtests.py -t scipy/signal/tests/test_peak_finding --no-build
--coverage

b) and using the `coverage` package
$ coverage run -m pytest scipy/signal/tests/test_peak_finding.py
$ coverage html

This approach is based on this blog post:
http://blog.behnel.de/posts/coverage-analysis-for-cython-modules.html

In both cases a) and b) the PYX file sadly isn't included in the report
and I don't know what to try next. Has anyone figured out a way to do
this? If I've overlooked a related issue or conversation on the mailing
list I apologize and would be grateful if you could point me to it.

Best regards,
Lars