I've found what looks like a bug wherein if you are using an ssh alias for a git remote, and that remote has a dash in its name, and you specify the target path as the name of the url itself, git complains about refs not being valid packed references. To reproduce, in git 2.1.0 and with a repository using ssh config and which has a dash in the name, e.g.: > git clone github:nixme/pry-nav "github:nixme/pry-nav" Cloning into 'github:nixme/pry-nav'... done. ror: internal error: refs/remotes/origin/master is not a valid packed reference! error: internal error: refs/tags/v0.0.1 is not a valid packed reference! error: internal error: refs/tags/v0.0.2 is not a valid packed reference! error: internal error: refs/tags/v0.0.3 is not a valid packed reference! error: internal error: refs/tags/v0.0.4 is not a valid packed reference! error: internal error: refs/tags/v0.1.0 is not a valid packed reference! error: internal error: refs/tags/v0.2.0 is not a valid packed reference! error: internal error: refs/tags/v0.2.1 is not a valid packed reference! error: internal error: refs/tags/v0.2.2 is not a valid packed reference! error: internal error: refs/tags/v0.2.3 is not a valid packed reference! error: internal error: refs/tags/v0.2.4 is not a valid packed reference! error: Trying to write ref refs/heads/master with nonexistent object f0e17451f0bd508f408d4fdda97e3a131d11f696 fatal: Cannot update the ref 'HEAD' The ssh config for github (not that it matters, but for completeness) is: Host github user git hostname github.com I have confirmed that if the repository url does not have a dash, this works as expected. I have also downgraded to 2.0.4 and found that again, this works as expected. Beyond this I have not narrowed the scope. For now, I've downgraded my version of git and so have not tested beyond this. Chris Salzberg -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html