I am trying to maintain a bare copy of a Git repository and having some issues keeping the remote tracking branches up to date. I create the remote tracking branches like this:

git branch -t 0.1 origin/0.1

This seems to do what I need to do for that point in time. However, if I make changes to origin and then fetch with the bare repo, things start to fall apart. My workflow looks like this:

git fetch origin

It looks like all of the commits come in at that point, but my local copy of 0.1 is not being updated. I can see that the changes have been brought into the repository by doing the following:

git diff 0.1 refs/remotes/origin/0.1

What do I need to do to get my tracking branch updated with the remote's updates? I feel like I must be missing a step or a flag somewhere.