git branch performance problem?

Hello,

I'm seeing very slow performance with 'git-branch'. Is this the canonical way to find out the current branch? ( I know I can look into .git/HEAD, but how likely is that to break in the future?)

hanwen@lilypond:/tmp/z$ time git branch
* foo
  master

real 0m0.307s user 0m0.232s sys 0m0.038s

hanwen@lilypond:/tmp/z$ git --version git version 1.5.1.rc1.949.g322bc

On NFS this takes 5 seconds. Note that I have a humongous amount of remotes, but those should not be examined without -r, right?

hanwen@lilypond:/tmp/z$ find .git/refs/remotes | wc -l 1856