This is PR #11950: https://github.com/servo/servo/pull/11950
Re:Servo Nightly Builds Available
by Manishearth on Friday July 01, 2016 @02:45AM
(#12014281)
https://github.com/servo/servo/pull/11950 ,
should get fixed in a few days
Happy to see a nightly already, I must read the source at some point :)