Called process error output doesn’t all go to stderr · Issue #6651 · pypa/pip (original) (raw)

pip 19.1.1, Python: 3.8-dev, Ubuntu xenial

My travis build with Python 3.8 fails: https://travis-ci.org/theislab/scanpy/jobs/550248884#L285

The error occurs when trying to install scipy’s build requirements via pyproject.toml. Confusingly, it reports an environment marker not matching (and the subsequent ignoring of the dependency) as an error:

Installing build dependencies ... error
ERROR: Complete output from command
       …/python …/pip install --ignore-installed --no-user --prefix …/overlay \
       --no-warn-script-location --no-binary :none: --only-binary :none: \
       -i https://pypi.org/simple -- wheel setuptools 'Cython>=0.29.2' \
       'numpy==1.13.3; python_version=='"'"'3.5'"'"'' \
       'numpy==1.13.3; python_version=='"'"'3.6'"'"'' \
       'numpy==1.14.5; python_version>='"'"'3.7'"'"'':
ERROR: Ignoring numpy: markers 'python_version == "3.5"' don't match your environment 
Ignoring numpy: markers 'python_version == "3.6"' don't match your environment

As you can see, the subsequent ignoring of the second line is not reported as an error (as I would expect).