logilab-common #281908 pytest.replace_trace does not work with pycoverage [validation pending]

due to a bug in pycoverage https://bitbucket.org/ned/coveragepy/issue/123 one cannot use sys.settrace for the tracer function injected by the cTracer object of pycoverage.

This breaks coverage tests of every test using testlib...

priorityimportant
typebug
done in0.63.2
load0.500
load left0.000
closed by#18d7d467614a [coverage] fix a bug breaking coverage.py (closes #281908)