error: * Ignoring funny ref 'refs/heads/' locally

From: Jon Seymour <jon.seymour@gmail.com>
Date: Jun 17, 2009, 12:08 UTC
Message-ID: <2cfc40320906170508o4fc0fc14sca511742be03ee5@mail.gmail.com>

Can someone tell me why this happens?

    error: * Ignoring funny ref 'refs/heads/' locally

It also happens with 1.6.3.1

$ mkdir root
$ cd root
$ git init
Initialized empty Git repository in /tmp/root/.git/
$ :> .gitignore
$ git add .gitignore
$ git commit -m "initial"
Created initial commit 6a7c768: initial
 0 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 .gitignore
$ cd ..
$ git clone root clone
Initialized empty Git repository in /tmp/clone/.git/
$ cd clone
$ git fetch origin :
error: * Ignoring funny ref 'refs/heads/' locally
$ git --version
git version 1.6.0.4
$ exit