obadz 47950b5353 modules/misc/version.nix: populate nixosRevision based on <nixpkgs/.git> when possible (#15624)
Example:

$ nixos-option system.nixosLabel
Value:
"16.09.git.4643ca1"
2016-05-24 23:34:28 +01:00
..
2016-02-26 22:15:41 +00:00
2015-11-15 03:41:39 +08:00
2016-03-09 15:25:53 -03:00
2016-03-10 12:31:05 +00:00
2016-05-20 19:46:20 +00:00
2014-03-10 15:01:56 +01:00
2016-02-26 22:15:40 +00:00
2016-05-19 01:26:04 +03:00
2016-02-26 22:15:41 +00:00