I really know nothing about git except how to use it to grab a copy of some code from Github. Running that git command in either my bitcoin-abe directory or its parent isn't showing anything, so I must have moved things around enough that git became confused. I can see in my command history where I fetched Abe using "git clone," so I know that's how I originally got it.
Please pull the latest and see if it gets you past the error. I would have pushed it earlier but did not have my github keys handy.
Thanks.