Today I ran a 'git push' to shove my commits from my local repository into a new created and empty main remote repo, the result was this (I've created a completely new local repo, the command "git push -u origin master" would solve this problem (it's also on a github introduction page)):
No refs in common and none specified; doing nothing.
Perhaps you should specify a branch such as 'master'.
fatal: The remote end hung up unexpectedly
error: failed to push some refs to 'email@example.com:yourname/test.git'
It is my understanding that the core issue is that there are no files in common between the original remote repo you cloned (empty) and the one on-disk. Doing the git-push-origin-master shoves your repo up into the empty repository and gives you that common base again so you can do a 'git push' without issue.
The full explanation is here: http://www.thebuzzmedia.com/git-tip-git-push-no-refs-in-common-and-none-specified/