清理旧的远程 git 分支

git push origin :heads/devel

git branch -d devel
master
origin/HEAD
origin/master
git branch -d devel
git push origin :heads/devel

error: unable to push to unqualified destination: heads/proxy3d
The destination refspec neither matches an existing ref on the remote nor
begins with refs/, and we are unable to guess a prefix based on the source ref.
fatal: The remote end hung up unexpectedly

答案