error: refname refs/heads/master not found fatal: Branch rename failed github code example

Example 1: error: refname refs/heads/master not found

I get into this issue too. The reason is that I didn't have any commit on this 
git repository.

When I run the command git branch -M main. I get the following error message.

	error: refname refs/heads/master not found
	fatal: Branch rename failed

After I add my first commit by the following command, all things works.

	git add .
	git commit -m 'Init'

Example 2: error: refname refs/heads/master not found

error: refname refs/heads/HEAD not found
fatal: Branch rename failed

$ git checkout -b main