Completely unrelated side note, but there is actually something called HgLab. It might even be older than GitLab? I came across it much earlier than GitLab anyway. It is a shame it didn't really take off, I've always preferred mercurial over git and my company requires us to self-host.
Have you looked at RhodeCode ? It's very similar like Gitlab with free Community Edition version that is also open-sourced. It's dedicated for self-hosting.
