I have a job I changed to build from a tag. However, I'd left the polling enabled. I noticed that the job built every time that it polled. The polling log shows:

Started on Jun 3, 2014 7:20:00 PM
Using strategy: Default
[poll] Last Built Revision: Revision aacfd8d1828633ccfb7ced255e795a29e31d6228 (mytag)
> git ls-remote -h git@hostname:my/project mytag
Done. Took 0.39 sec
Changes found

I noticed that the ls-remote command is being passed "-h", which I believe is causing the issue. The -h would exclude tags. Thus:

$ git ls-remote -h git@hostname:my/project mytag

Yields no results, but removing the "-h":

$ git ls-remote git@hostname:my/project mytag
aacfd8d1828633ccfb7ced255e795a29e31d6228 refs/tags/mytag