[BUG] git-mv submodule failure

project
  .git
  file1
  submoudle
     .git
      file2

$ cd project $ git-mv submodule submodule1 fatal: source directory is empty, source=submodule, destination=submodule1

However, the following is ok and rename is automatically detected $ cd project $ mv submodule submodule1 $ git-add submodule1 $ git-commit -a

which gives in vim: # Please enter the commit message for your changes. # (Comment lines starting with '#' will not be included) # On branch master # Changes to be committed: # (use "git reset HEAD <file>..." to unstage) # # renamed: submodule -> submodule1 #