Git and mercurial abort: revision cannot be pushed

29 Sep 2014

I’ve been migrating some repositories from Mercurial to Git; as part of this migration process some users want to keep using Mercurial locally until they have time to learn git.

First install the hg-git tools; for example on Ubuntu:

sudo aptitude install python-setuptools python-dev
sudo easy_install hg-git

Make sure the following is in your ~/.hgrc:

[extensions]
hgext.bookmarks =
hggit = 

Then, in your existing mercurial repository, add a new remote that points to the git repository. For example for a BitBucket repository:

cd <mercurial repository>
cat .hg/hgrc
[paths]
# the original hg repository
default = https://username@abcde.org/foo/barhg
# the git version (on BitBucket in this case)
bbgit   = git+ssh://git@bitbucket.org:foo/bar.git

Then you can go an hg push bbgit to push from your local hg repository to the remote git repository.

mercurial abort: revision cannot be pushed

You may get the error mercurial abort: revision cannot be pushed since it doesn’t have a ref when pushing from hg to git, or you might notice that your hg work isn’t being pushed. The solution here is to reset the hg bookmark for git’s master branch:

hg book -f -r tip master
hg push bbgit

If you find yourself doing this regularly, this small shell function (in your ~/.bashrc) will help:

hggitpush () {
   # $1 is hg remote name in hgrc for repo
   # $2 is branch (defaults to master)
   hg book -f -r tip ${2:-master}
   hg push $1
}

Then from your shell you can run commands like:

hggitpush bbgit dev
hggitpush foogit      # defaults to pushing to master