Git: refname 'master' is ambiguous

Question

I\'ve looked at all of the other ambiguous refname questions and none of them seem to help. Why am I getting this warning?

$ git checkout master
warning: ref         


        

Answer 1

This just happened to me. I somehow had a file .git/master containing a sha. Not sure how that got there, but when I deleted it, the error went away. If you read the accepted answer carefully, this is "expected behavior" but you won't see that .git/master if you do e.g. git show-ref master because it follows slightly different rules.