Basically, a developer for Opal made an off-color comment on Twitter, in his spare time. Because he had "Developer for Opal" on his Twitter profile, users that were offended made a bug report about it :
From there after a long string of drama, Github introduced a Code of Conduct, but it contained language such as "We will not act on Reverse Racism" (aka, non-priviledge races making harassing/defaming comments about whites) and other bigoted "progressive" ideals.
They were massively called out on it, and it created a schism in the community between people who believe things like "Can't be sexist towards males/can't be racist towards whites" and people who call out such idealogies as Bigoted.
It ended with the CoC going into limbo :
All relevant issues opened about Bigoted language in the CoC are linked in that issue. You can basically thank the people behind Contributor_Convenant that are trying to poison the Open Source community at large with the same trite that happened to the Atheism scene in 2010-2011 and to Occupy Wallstreet.
Apparently, the words of Bill and Ted aren't enough anymore : Be excellent to each other.