Can't push local changes to an existing remote branch

Question

There is a remote branch called "my-remote" that I had previously pushed to with no problem. As of today, I can't push and I get different errors.

First error I got was:

hint: Updates were rejected because a pushed branch tip is behind its remote
hint: counterpart. If you did not intend to push that branch, you may want to
hint: specify branches to push or set the 'push.default' configuration
hint: variable to 'current' or 'upstream' to push only the current branch.

I did some research and ran this hoping it would solve the problem:

git config push.default tracking

after running that I ran the push again:

git push https://github.com/someurl/mybranch.git

I got the following error:

pushing to remote 'https://github.com/someurl/mybranch.git', which is not the upstream of
your current branch 'my-remote', without telling me what to push
to update which remote branch.

I have tried running this:

git push master:my-remote https://github.com/someurl/mybranch.git

but it tells me that:

fatal: remote part of refspec is not a valid name in https://github.com/someurl/mybranch.git

Answer 1

If you want to push your master branch on the my-remote remote branch, the correct syntax would be:

 git push https://github.com/someurl/mybranch.git master:my-remote 

(first: remote repo reference, the refspec, from git push man page)

Regarding your first error message, if it really didn't tell you to merge, then a git pull --rebase might have been needed.
Or at least a:

 git config --global push.default current

(As mentioned in "Configure Git to Only Push Current Branch").

If you are in the local branch 'my-remote' (which is the case, according to the command), you can make sure the upstream branch is set by making a:

git push -u https://github.com/someurl/mybranch.git my-remote:my-remote