The requirement's constraint for `pythonPackages.keyring` didn't allow keyring v11. However it has been bumped in 93a16a2ace by @FRidh. Current failure: https://nix-cache.s3.amazonaws.com/log/2nw5adfx86jwiax32mn11kqpc35xwhsh-bonfire-unstable-2017-01-19.drv See ticket #36453
93a16a2ace