Using == in setup.py from requirements.txt will cause conflicts with other python packages

[squeaky-pl]

requirements.txt with == operator is meant to be used when you need completely limit the versions of package. fig uses requirements.txt input in setup.py to fill install_requires. If any package installed after fig requires other version or updates the dependency things will break.

fig up -d
Traceback (most recent call last):
  File "/usr/local/bin/fig", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2749, in <module>
    working_set = WorkingSet._build_master()
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 446, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 459, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 628, in resolve
    raise DistributionNotFound(req)
pkg_resources.DistributionNotFound: requests==2.2.1

The latest version of requests package available is 2.3.0 (which was installed in this case) and it's of course backward compatibile. You should either stop relaying on reading requirements.txt or start using >= operator.

[dnephin]

requirements.txt should actually contain a full list of pinned versions (using ==). That way tests can run against a specific version each time, and you have a way to build a virtualenv with known working dependencies.

I think the problem here is that setup.py uses the list from requirements.txt for install_requires, which is not correct. setup.py should use >=, <

Reference: https://caremad.io/blog/setup-vs-requirement/

[bfirsh]

@squeaky-pl are you using the binary distribution or installing with pip, out of curiosity?

[squeaky-pl]

@bfirsh, I am installing with pip from an ansible playbook.