$ git branch -C pommi # works fine, creates branch forcibly out of currently checkedout branch.
$ git branch -C pommi master # gives error, why???
fatal: Cannot force update the current branch.
I know that -C is for forcibly copying the branch, when a branch already exists with the same name. How can I create a force copy by explicitly specifying the branch name(which is not checked out) of the source branch to copy?