Hi Ralf, On Sun, 6 Jan 2019 at 22:06, Ralf Gommers <ralf.gomm...@gmail.com> wrote: > > > > On Sun, Jan 6, 2019 at 12:45 PM Thomas Robitaille > <thomas.robitai...@gmail.com> wrote: >> >> Hi all, >> >> Back in December I started getting failures in continuous integration >> as well as reports of failures from users of installation issues for a >> couple of packages. The problem can be easily reproduced in a Docker >> container with: >> >> FROM ubuntu:16.04 >> RUN apt-get update >> RUN apt-get install -y python3 python3-dev python3-pip python3-wheel >> RUN pip3 install fast-histogram >> RUN python3 -c 'import fast_histogram' >> >> Doing this results in the following traceback: >> >> ImportError: No module named 'numpy.core._multiarray_umath' >> Traceback (most recent call last): >> File "<string>", line 1, in <module> >> File >> "/usr/local/lib/python3.5/dist-packages/fast_histogram/__init__.py", >> line 1, in <module> >> from .histogram import * >> File >> "/usr/local/lib/python3.5/dist-packages/fast_histogram/histogram.py", >> line 7, in <module> >> from ._histogram_core import (_histogram1d, >> ImportError: numpy.core.multiarray failed to import >> >> I've seen similar issues with other packages too. The key is that the >> fast-histogram package defines: >> >> setup_requires=['numpy'] >> >> in the setup.py (since the package has a C extension that uses the >> Numpy C API) and numpy is needed before the install_requires >> dependencies are installed: >> >> https://github.com/astrofrog/fast-histogram/blob/master/setup.py >> >> Now this normally works fine, but the issues I saw started when the >> first 1.16 RC was made available, when installing into an environment >> in which numpy is not already installed. >> >> My understanding is that setup_requires is honored by easy_install >> (even if installing the main package with pip), which doesn't ignore >> pre-releases. Thus, the package is built against the 1.16 RC but then >> 1.15 is installed due to: >> >> install_requires=['numpy'] >> >> which is honored by pip. > > > Oh fun. Thanks for explaining this! > >> >> I think that the correct solution is to make sure that: >> >> [build-system] >> requires = ["setuptools", "wheel", "numpy"] >> >> is added to the pyproject.toml file (as per PEP 518). > > > To clarify: you're talking about fast-histogram's pyproject.toml file right?
Yes that's right. Just for the record, here's the pull request to fast-histogram to implement the fix: https://github.com/astrofrog/fast-histogram/pull/33 Cheers, Tom > >> This then works >> properly with recent versions of pip (>10 I think). I think removing >> setup_requires then makes sense because it'd be better to have an >> error with older versions of pip that numpy is not installed rather >> than having the package built against the wrong version. > > > This is a pretty hacky solution, needed because pip doesn't support > setup_requires, but yes it should work and I can't think of a better way. > > Cheers, > Ralf > > >> >> I know this is a temporary issue in the sense that it will go away >> once the final version of 1.16 is out, but I just wanted to share this >> as a heads-up in case you get reports of issues from other people, and >> also to check whether there are any other solutions/workarounds to be >> aware of? (to avoid a similar situation in future). >> >> Thanks, >> Tom >> _______________________________________________ >> NumPy-Discussion mailing list >> NumPy-Discussion@python.org >> https://mail.python.org/mailman/listinfo/numpy-discussion > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@python.org > https://mail.python.org/mailman/listinfo/numpy-discussion _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@python.org https://mail.python.org/mailman/listinfo/numpy-discussion
