$ git remote set-url cbaines http://git.cbaines.net/guix
$ git fetch cbaines
error: wrong index v2 file size in
.git/objects/pack/pack-739d9ab6fbe9233657458397a3ab1f0ad30107f1.idx.temp
error: Unable to find 289e6cffc4ed9a6658e85b22635ea2fd3126bc3f under
http://git.cbaines.net/guix
Cannot obtain needed object 289e6cffc4ed9a6658e85b22635ea2fd3126bc3f
error: fetch failed.
This should work though, could you try again, perhaps try cloning the
entire repository if adding it as a remote doesn't work. I ran git fsck
and git gc on the server, just in case there was a problem there.