git error: src refspec master does not match any. error: failed to push some refs to etc

Have you seen this error?
error: src refspec master does not match any.
error: failed to push some refs to …
It may be annoyingly simple.
Some repositories do not have a master branch – Drupal modules for example make you remove the master branch and instead use 7.x-1.x etc.
So – in that case – the command to run is:
git push origin 7.x-1.x
HTH!