git clean is not removing a submodule added to a branch when switching branches

If I add a submodule to a branch and then switch branches, git checkout warns it cannot remove the submodule. If I then issue a git clean - it says it removes the submodule but in fact does nothing at all. Is this a bug or expected behaviour.

TIA

Adrian

Below are cut&paste steps to reproduce.

git --version #git version 1.7.8.4

git init submod cd submod echo "This is a submodule" > README.txt git add . git commit -m "Initial commit" cd .. git init prog cd prog echo "This is a program" > README.txt git add . git commit -a -m "Initial commit" git checkout -b topic1 git submodule add ../submod git commit -m "Added submodule"

git checkout master #warning: unable to rmdir submod: Directory not empty #Switched to branch 'master'

git status # On branch master # Untracked files: # (use "git add <file>..." to include in what will be committed) # # submod/ #nothing added to commit but untracked files present (use "git add" to track)

git clean -fd #Removing submod/

git status # On branch master # Untracked files: # (use "git add <file>..." to include in what will be committed) # # submod/ #nothing added to commit but untracked files present (use "git add" to track)