warning: unable to rmdir my/module: Directory not empty

Hi all,

  Does anyone knows where is this warning is coming from:

warning: unable to rmdir my/module: Directory not empty

  I have a git master, an empty branch and a submodule on master.
Switching from master to my 'empty' branch always trigger this
warning. Here are some steps to reproduce the issue (*). I am using a
debian stable system + backports and version is:

$ git --version git version 1.7.1

Thanks -Mathieu

(*) # master cd /tmp mkdir test cd test git init touch README git add README git commit -mREADME

# submodule cd .. mkdir module cd module git init touch MODULE git add MODULE git commit -mMODULE

cd ../test git submodule add file:///tmp/module my/module git commit -a -m"adding submodule"

# create an empty branch git symbolic-ref HEAD refs/heads/newbranch rm .git/index git clean -fdx touch EMPTY git add EMPTY git commit -a -mEMPTY

# update git checkout master git submodule init git submodule update git checkout newbranch