gistfile1.txt

dennis@spirit:~/code/git$ git status
On branch nd/multiple-work-trees
nothing to commit, working directory clean
dennis@spirit:~/code/git$ cat .git/HEAD 
ref: refs/heads/nd/multiple-work-trees
dennis@spirit:~/code/git$ git checkout HEAD^
Note: checking out 'HEAD^'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:

  git checkout -b <new-branch-name>

HEAD is now at b2cc490... git-checkout.txt: a note about multiple checkout support for submodules
dennis@spirit:~/code/git$ git status
HEAD detached at b2cc490
nothing to commit, working directory clean
dennis@spirit:~/code/git$ cat .git/HEAD 
b2cc49067b2d3635ef972771523cd77735c6af33