nix-shell -p gobjectIntrospection 'python2.withPackages (ps: with ps; [ pygobject3 atk gtk3 ])' --run "python -c \"import pygtkcompat; pygtkcompat.enable_gtk(version='3.0')\""
these paths will be fetched (0.65 MiB download, 7.58 MiB unpacked):
  /nix/store/8sd2wsv48qmhzn61ws05952rr43rsg60-gobject-introspection-1.56.0-dev
copying path '/nix/store/8sd2wsv48qmhzn61ws05952rr43rsg60-gobject-introspection-1.56.0-dev' from 'https://cache.nixos.org'...
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/nix/store/r09qmzqmcv6m3zkl9z8pbj908kl4ckb5-python-2.7.14-env/lib/python2.7/site-packages/pygtkcompat/pygtkcompat.py", line 140, in enable_gtk
    gi.require_version('Atk', '1.0')
  File "/nix/store/r09qmzqmcv6m3zkl9z8pbj908kl4ckb5-python-2.7.14-env/lib/python2.7/site-packages/gi/__init__.py", line 130, in require_version
    raise ValueError('Namespace %s not available' % namespace)
ValueError: Namespace Atk not available