beets: ImportError: "six"

[kierdavis]

Issue description

After updating to the latest version of the nixos-unstable channel, I found that beets crashes on startup with the following stacktrace:

Traceback (most recent call last):
  File "/nix/store/7jhnkwyidrgmarakhdp4mxx23mv7xp04-beets-1.4.1/bin/.beet-wrapped", line 8, in <module>
    from beets.ui import main
  File "/nix/store/7jhnkwyidrgmarakhdp4mxx23mv7xp04-beets-1.4.1/lib/python2.7/site-packages/beets/__init__.py", line 20, in <module>
    from beets.util import confit
  File "/nix/store/7jhnkwyidrgmarakhdp4mxx23mv7xp04-beets-1.4.1/lib/python2.7/site-packages/beets/util/__init__.py", line 31, in <module>
    import six
ImportError: No module named six

This issue also appears to be present on nixpkgs master branch.

Steps to reproduce

git clone https://github.com/NixOS/nixpkgs.git
cd nixpkgs
nix-build -A beets
result/bin/beet

Technical details

• System: NixOS 17.03pre96717.69bee1b (Gorilla)
• Nix version: 1.11.4
• Nixpkgs version: 17.03pre96799.571cf4f2

[kierdavis]

cc the maintainers @aszlig @domenkozar @pjones @Profpatsch

[FRidh]

Maybe related to the regression I caused (#20943). Testing now.

[FRidh]

Nope, six was simply missing. I'll push a fix.

[kierdavis]

Thanks, that fixed it.