[github] Github "Updates were rejected because the remote contains work that you do not have locally."

The supplied answers didn't work for me.

I had an empty repo on GitHub with only the LICENSE file and a single commit locally. What worked was:

$ git fetch
$ git merge --allow-unrelated-histories
Merge made by the 'recursive' strategy.
 LICENSE | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 LICENSE

Also before merge you may want to:

$ git branch --set-upstream-to origin/master
Branch 'master' set up to track remote branch 'master' from 'origin'.