git-remote-hg is the semi-official Mercurial bridge from the Git project, once installed, it allows you to clone, fetch and push to and from Mercurial repositories as if they were Git ones:

git clone "hg::http://selenic.com/repo/hello"

To enable this, simply add the git-remote-hg script anywhere in your $PATH:

curl https://raw.githubusercontent.com/felipec/git-remote-hg/master/git-remote-hg -o ~/bin/git-remote-hg
chmod +x ~/bin/git-remote-hg

That’s it :)

Obviously you will need Mercurial installed.

Configuration

If you want to see Mercurial revisions as Git commit notes:

% git config core.notesRef refs/notes/hg

If you are not interested in Mercurial permanent and global branches (aka. commit labels):

% git config --global remote-hg.track-branches false

With this configuration, the 'branches/foo' refs won’t appear.

If you want the equivalent of hg clone --insecure:

% git config --global remote-hg.insecure true

If you want git-remote-hg to be compatible with hg-git, and generate exactly the same commits:

% git config --global remote-hg.hg-git-compat true

Notes

Remember to run git gc --aggressive after cloning a repository, especially if it’s a big one. Otherwise lots of space will be wasted.

The newest supported version of Mercurial is 6.2, the oldest one is 4.0.

Pushing branches

To push a branch, you need to use the 'branches/' prefix:

% git checkout branches/next
# do stuff
% git push origin branches/next

All the pushed commits will receive the "next" Mercurial named branch.

Note: Make sure you don’t have remote-hg.track-branches disabled.

Cloning HTTPS

The simplest way is to specify the user and password in the URL:

git clone hg::https://user:password@bitbucket.org/user/repo

You can also use the schemes extension:

[auth]
bb.prefix = https://bitbucket.org/user/
bb.username = user
bb.password = password

Finally, you can also use the keyring extension.

Caveats

The only major incompatibility is that Git octopus merges (a merge with more than two parents) are not supported.

Mercurial branches and bookmarks have some limitations of Git branches: you can’t have both 'dev/feature' and 'dev' (as Git uses files and directories to store them).

Multiple anonymous heads (which are useless anyway) are not supported: you would only see the latest head.

Closed branches are not supported: they are not shown and you can’t close or reopen. Additionally in certain rare situations a synchronization issue can occur (Bug #65).

Limitations of Git’s remote-helpers framework apply.

Other projects

There are other git-remote-hg projects out there, but this is the original, which was distributed officially in the Git project.

Over the years many similar tools have died out, the only actively maintained alternative is mnauw’s fork of this project: mnauw/git-remote-hg. I’ve merged some of his patches, and he has merged some of my patches, so the projects are mostly in sync, but not quite. In particular Nauwelaerts' fork has many administrative extensions, which although useful to some people, I don’t believe they belong in the core.

For a comparison between these and other projects go here.

Contributing

Send your patches to the mailing list git-fc@googlegroups.com (no need to subscribe).