This is not an issue, but just an idea.
I wonder if it would be nice to migrate the gd repository to git, because mercurial lacks some useful features git has, e.g. http://www.emilsit.net/blog/archives/git-is-more-usable-than-mercurial/. And I think GD developers are all familiar with git :)
For instruction to convert hg repositories to git on bitbucket, you may find http://blog.bitbucket.org/2011/10/05/converting-hg-repositories-to-git/.
But hg-fast-export is an easier alternative to do that: http://hedonismbot.wordpress.com/2008/10/16/hg-fast-export-convert-mercurial-repositories-to-git-repositories/ It can maintain all logs as well as tags in the original repository.
Thank you for your consideration.