dogpile.cache 1.0.0 cannot be installed on Python 3.5 because stevedore requires 3.6+

[RazerM]

Trying to install dogpile.cache in a python:3.5 docker image yields the following error:

root@3b09b5b38442:/# pip install dogpile.cache
Collecting dogpile.cache
  Using cached dogpile.cache-1.0.0.tar.gz (339 kB)
Collecting decorator>=4.0.0
  Using cached decorator-4.4.2-py2.py3-none-any.whl (9.2 kB)
ERROR: Could not find a version that satisfies the requirement stevedore>=3.0.0 (from dogpile.cache) (from versions: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.7.1, 0.7.2, 0.8, 0.9, 0.9.1, 0.10, 0.11, 0.12, 0.13, 0.14, 0.14.1, 0.15, 1.0.0.0a2, 1.0.0, 1.1.0, 1.2.0, 1.3.0, 1.4.0, 1.5.0, 1.6.0, 1.7.0, 1.8.0, 1.9.0, 1.10.0, 1.11.0, 1.12.0, 1.13.0, 1.14.0, 1.15.0, 1.16.0, 1.17.0, 1.17.1, 1.18.0, 1.19.0, 1.19.1, 1.20.0, 1.20.1, 1.21.0, 1.22.0, 1.23.0, 1.24.0, 1.25.0, 1.25.1, 1.25.2, 1.26.0, 1.27.0, 1.27.1, 1.28.0, 1.29.0, 1.30.0, 1.30.1, 1.31.0, 1.32.0)
ERROR: No matching distribution found for stevedore>=3.0.0 (from dogpile.cache)

[zzzeek]

well we probably have to bump dogpile.cache to 3.6 then, no mystery there. cc @dhellmann

[dhellmann]

You could use conditional requirements to specify a different version of stevedore for older dogpile.cache.

Something like:

stevedore>=2.0.0,<3.0.0; python_version<'3.6'
stevedore>=3.0.0; python_version>='3.6'

[zzzeek]

Why don't we just make the requirement "stevedore>=2.0.0" across the board? if they are on a newer python they will get the newer stevedore unless they have an old version still lying around, in which case, that still works they just have fewer features.

[sqla-tester]

Mike Bayer has proposed a fix for this issue in the master branch:

Lower stevedore minimum version to 2.0.0 https://gerrit.sqlalchemy.org/c/sqlalchemy/dogpile.cache/+/2101

[RazerM]

stevedore 2.0 can't be installed on 3.5 either. I don't mind if dogpile.cache 1.0.1 requires 3.6, but could you yank 1.0.0 once it's released so that pip will install 0.9.2 on Python 3.5?

[zzzeek]

guess we have to do that too.

[zzzeek]

so we will pin to 3.6 but I also have to figure out how to do #185

[zzzeek]

what's the difference between "yank" and "delete" on Pypi? I did a yank.

[RazerM]

yank doesn’t prevent pip installing that exact version when requested, but it won’t choose that version on its own. I.e. 3.6 users who pinned 1.0.0 can keep using it and 3.5 users who didn’t pin a version will get 0.9.2