On 19 July 2018 at 11:02, Bernat Gabor email@example.com wrote:
Sorry to bump into this so late, but:
Would not 2a be more backward compatible than 2b? I mean people may have build environments/installs doing:
- pip install setuptools-scm setuptools pbr
- pip install os-system-level
This way you can bypass the setup requires of setuptools to use easy_install. With 2b there is no way to avoid setup requires elements to not trigger easy install; other than os-system-level (which requires pbr for setup) to switch to pyproject.toml.
For tools (such as pip) where 2a and 2b behave differently, yes it would. But that's a pip implementation decision which can be made independently of the resolution of this discussion (the PEP allows either behaviour). The details of pip's behaviour have been discussed both on this thread and on the related pip issue that's referenced in this thread. I don't think it's worth rehashing that discussion again here.
If you want to argue that pip should switch to behaviour 2a, you should pick up the discussion on the pip issue tracker. But be warned, I'll argue against you over there :-) (Not least because the legacy behaviour is available using --no-build-isolation, which is *precisely* for the case where you want to manage the build tools manually the way you are doing above).