git show "previous tag"

[Andrew Edwards via Digitalmars-d]

On 8/29/14, 10:55 AM, Dicebot wrote:
> On Thursday, 28 August 2014 at 05:13:06 UTC, Andrei Alexandrescu wrote:
>> On 8/27/14, 9:47 PM, Andrew Edwards wrote:
>>> Anyone here knows how to consistently obtain the previous tag on git?
>>
>> Are tags always coming in order? Then it's easy:
>>
>> git tag | tail -n2 | head -n1
>>
>>
>> Andrei
>
> Not in semver order unfortunately. This will be changed in new git
> version though (http://blogs.atlassian.com/2014/08/whats-new-git-2-1/)
>
> Andrew, what is your desired definiton of "prior"? This `git abbrev`
> command finds previos named commit by traversing _commit_ history. If it
> returns v2.066.0-b1 that means that this tag was created later in the
> commit sequence than v2.066.0 (which is not surprising)


By prior I'm referring to the tag created immediately before the one I'm 
using in querying. If I'm building v2.066.0-rc1, I'm expecting back 
v2.066.0-b6. Likewise, if I provide v2.066.0-b1 it should return v2.065.0.

There was a slight snafu that required recreating the beta 2 and 3 tags 
for the 2.066 release. This occurred right before beta 4 was created. 
All other tags were created without problems following that this so 
might be a bug in the github system. The very last tag I created on the 
2.066 branch was v2.066.0 which is what I created the release with.

This command:

git for-each-ref --sort=taggerdate --format '%(refname) %(taggerdate)'

performed on the installer repo lists the available tags in the order 
they were created:

	refs/tags/v2.065-b1 Sat Jan 18 00:56:41 2014 -0500
	refs/tags/v2.065.0-b2 Fri Jan 24 22:16:50 2014 -0500
	refs/tags/v2.065.0-b3 Mon Feb 3 03:21:32 2014 -0500
	refs/tags/v2.065.0-rc1 Sun Feb 16 21:43:37 2014 -0500
	refs/tags/v2.065.0 Sun Feb 23 22:10:15 2014 -0500
	refs/tags/v2.066.0-b1 Wed Jul 2 06:53:47 2014 +0900
	refs/tags/v2.066.0-b2 Tue Jul 15 17:55:57 2014 +0900
	refs/tags/v2.066.0-b3 Tue Jul 15 17:58:35 2014 +0900
	refs/tags/v2.066.0-b4 Tue Jul 15 21:36:55 2014 +0900
	refs/tags/v2.066.0-b5 Mon Jul 21 17:26:57 2014 +0900
	refs/tags/v2.066.0-b6 Sun Jul 27 12:14:53 2014 +0900
	refs/tags/v2.066.0-rc1 Thu Jul 31 17:54:52 2014 +0900
	refs/tags/v2.066.0-rc2 Fri Aug 8 18:21:29 2014 +0900
	refs/tags/v2.066.0 Sat Aug 16 22:17:00 2014 +0900
	refs/tags/v2.067.0-b1 Tue Aug 26 10:52:01 2014 +0900

Note: I've truncated the list to show just the tags I created.