Re: Q: git describe --always --tags .. gives "warning: tag 'tag1' is really 'tag2' here"

From: Junio C Hamano <gitster@pobox.com>
Date: May 29, 2019, 18:01 UTC
Message-ID: <xmqqd0k1ywal.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <5CEE38B4020000A1000317C6@gwsmtp.uni-regensburg.de>

"Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de> writes:

> So I got the response:
> warning: tag 'isredir-0.3.0' is really 'iredir-0.3.0' here
> isredir-0.3.0-3-gaf467c7

I suspect that "git cat-file tag isredir-0.3.0" would begin like

	$ git cat-file tag iredir-0.3.0
	object .....
	type commit
	tag isredir-0.3.0
	tagger ...

Notice that "tag" line records the true name of that tag, which does not match where you stored that tag in refs/tags/ hierarchy?

While trying to describe af467c7 by following its ancestry and finding the ancestor three generations ago, the command found refs/tags/iredir-0.3.0 and then noticed that discrepancy, which is what the warning is about.

Imagine you have only v1.0.0 (which is with known issues) but somebody did "cd .git/refs/tags && mv v1.0.0 v1.1.0" in an attempt to fool you. The fact that your 'master' is a bit ahead of the commit that was tagged with the tag object (which is v1.0.0 but pretending to be v1.1.0) can be seen with "describe", but the command is careful enough to use the real version number (i.e. v1.0.0) and not the refname (i.e. v1.1.0).