Hi! pip 7 enables wheel caching by default, which is good.
Wheel caching means you can't compute dynamic dependencies any more -- i.e. things like setup( ... install_requires=[...] + (['enum34'] if sys.version_info[0] < 3 else []), ...) will cause problems. As far as I understand, you're supposed to use environment markers instead. Problem 1: where's the documentation? E.g. https://python-packaging-user-guide.readthedocs.org/en/latest/distributing/ has no mention of the word "marker". Try to google "setuptools environment marker" (and how is a user going to discover the magical keyword they need to google is "environment marker")? Try to find anything resembling documentation on the 1st page. The best I could find was http://docs.openstack.org/developer/pbr/#environment-markers which only works if you use pbr. Even the spec (https://www.python.org/dev/peps/pep-0426/#environment-markers) only shows how the markers are supposed to appear in the JSON metadata. No clue is provided for poor writers of setup.py files. I somehow discovered the syntax once (I don't remember how -- most likely kind people in #pypa spoon-fed me), but now I'm cargo-culting my existing setup.py files that already use environment markers. Problem 2: what are the minimum versions of the tools that your users must have before you can rely on environment markers? - setuptools >= 0.7 ("Added experimental environment marker support") - wheel >= 0.24 (if you have wheel 0.23 or older, environment markers are silently broken and have fun figuring out why: https://github.com/pypa/pip/issues/2870). - does the pip version matter at all? I think not; please correct me if I'm wrong. Some official answers from the hard-working PyPA visionaries would be welcome. Marius Gedminas -- I once held a little hand That made my sad heart sing. Twas the loveliest hand I'd ever held, Four Aces and a King
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_______________________________________________ Distutils-SIG maillist - Distutils-SIG@python.org https://mail.python.org/mailman/listinfo/distutils-sig