CoverageException: Can't combine line data with arc dat when using coverage with the pytest-cov pytest extension. I think this is similar to
#399, but that issue is closed.
Example failure on travis: https://travis-ci.org/samuelcolvin/arq/builds/148541711
The test causing problems is using click's
CliRunner, code here. The CLI command that's testing starts another process (using
multiprocessing.Process) to run the worker which is what's causing the problem, if you prevent the worker process being started the exception doesn't occur.
I tried changing the
concurrency mode but it made no difference.
To reproduce: clone,
pip install -e . && pip install -r tests/requirements.txt,
relevant bits of
click==6.6 coverage==4.2 pytest==2.9.2 pytest-cov==2.3.0
Let me know if you need anymore information.