On Monday, April 1, we'll migrate the enzo-dev repo from hg/bitbucket to git/github. I'll be heading up this process, but anyone who would like to help out or see how it's done is welcome to join in. I will get started at 11:00 AM Pacific time and will post a link to a google hangout on the Enzo slack channel.
In the meantime, please hold off on issuing new pull requests until after the migration. I will follow up with step-by-step instructions for migrating forks to github.