Re: fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree.

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 8, 2007, 10:33 UTC
Message-ID: <7vfy52ka63.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <20070608102113.GB2335@cip.informatik.uni-erlangen.de>

Thomas Glanzmann <thomas@glanzmann.de> writes:

> I see it. Last line. I tried to clone from a repository which itself had a
> detached HEAD. Could that be the problem?

Ah, our mails crossed.

There is no reason to forbid cloning of a repository whose HEAD is detached, but detached HEAD is a relatively recent invention, and I would not be surprised if that was indeed the breakage, nor nobody has hit this so far.

It's sufficiently late here so I do not think I would be able to take a look at it tonight, though. Sorry.

Just in case you need unblocking (although I think you know how already), you should be able to continue with:

	$ git rev-parse v2.6.20^0 >.git/HEAD
        $ git read-tree HEAD
        $ git checkout-index -f -q -u -a

That would give you a normal detached state at v2.6.20; you should be able to come back to your branches with usual "git checkout".