GIT-TAG(1) Git Manual GIT-TAG(1)NAMEgit-tag - Create, list, delete or verify a tag object signed with GPG
SYNOPSISgit-tag [-a | -s | -u <key-id>] [-f] [-m <msg> | -F <file>] <name> [<head>]
git-tag-d <name>...
git-tag [-n[<num>]] -l [<pattern>]
git-tag-v <name>...
DESCRIPTION
Adds a tag reference in .git/refs/tags/
Unless -f is given, the tag must not yet exist in .git/refs/tags/
directory.
If one of -a, -s, or -u <key-id> is passed, the command creates a tag
object, and requires the tag message. Unless -m <msg> or -F <file> is
given, an editor is started for the user to type in the tag message.
If -m <msg> or -F <file> is given and -a, -s, and -u <key-id> are
absent, -a is implied.
Otherwise just the SHA1 object name of the commit object is written
(i.e. a lightweight tag).
A GnuPG signed tag object will be created when -s or -u <key-id> is
used. When -u <key-id> is not used, the committer identity for the
current user is used to find the GnuPG key for signing.
OPTIONS-a Make an unsigned, annotated tag object
-s Make a GPG-signed tag, using the default e-mail address's key
-u <key-id>
Make a GPG-signed tag, using the given key
-f Replace an existing tag with the given name (instead of failing)
-d Delete existing tags with the given names.
-v Verify the gpg signature of the given tag names.
-n<num>
<num> specifies how many lines from the annotation, if any, are
printed when using -l. The default is not to print any
annotation lines. If no number is given to -n, only the first
line is printed.
-l <pattern>
List tags with names that match the given pattern (or all if no
pattern is given). Typing "git tag" without arguments, also
lists all tags.
-m <msg>
Use the given tag message (instead of prompting). If multiple -m
options are given, there values are concatenated as separate
paragraphs. Implies -a if none of -a, -s, or -u <key-id> is
given.
-F <file>
Take the tag message from the given file. Use - to read the
message from the standard input. Implies -a if none of -a, -s,
or -u <key-id> is given.
CONFIGURATION
By default, git-tag in sign-with-default mode (-s) will use your
committer identity (of the form "Your Name <your@email.address>") to
find a key. If you want to use a different default key, you can specify
it in the repository configuration as follows:
[user]
signingkey = <gpg-key-id>
DISCUSSION
On Re-tagging
What should you do when you tag a wrong commit and you would want to
re-tag?
If you never pushed anything out, just re-tag it. Use "-f" to replace
the old one. And you're done.
But if you have pushed things out (or others could just read your
repository directly), then others will have already seen the old tag.
In that case you can do one of two things:
1. The sane thing. Just admit you screwed up, and use a different name.
Others have already seen one tag-name, and if you keep the same
name, you may be in the situation that two people both have "version
X", but they actually have different "X"'s. So just call it "X.1"
and be done with it.
2. The insane thing. You really want to call the new version "X" too,
even though others have already seen the old one. So just use "git
tag -f" again, as if you hadn't already published the old one.
However, Git does not (and it should not) change tags behind users
back. So if somebody already got the old tag, doing a "git pull" on
your tree shouldn't just make them overwrite the old one.
If somebody got a release tag from you, you cannot just change the
tag for them by updating your own one. This is a big security issue,
in that people MUST be able to trust their tag-names. If you really
want to do the insane thing, you need to just fess up to it, and
tell people that you messed up. You can do that by making a very
public announcement saying:
Ok, I messed up, and I pushed out an earlier version tagged as X. I
then fixed something, and retagged the *fixed* tree as X again.
If you got the wrong tag, and want the new one, please delete
the old one and fetch the new one by doing:
git tag -d X
git fetch origin tag X
to get my updated tag.
You can test which tag you have by doing
git rev-parse X
which should return 0123456789abcdef.. if you have the new version.
Sorry for inconvenience.
Does this seem a bit complicated? It should be. There is no way that
it would be correct to just "fix" it behind peoples backs. People
need to know that their tags might have been changed.
On Automatic following
If you are following somebody else's tree, you are most likely using
tracking branches (refs/heads/origin in traditional layout, or
refs/remotes/origin/master in the separate-remote layout). You usually
want the tags from the other end.
On the other hand, if you are fetching because you would want a
one-shot merge from somebody else, you typically do not want to get
tags from there. This happens more often for people near the toplevel
but not limited to them. Mere mortals when pulling from each other do
not necessarily want to automatically get private anchor point tags
from the other person.
You would notice "please pull" messages on the mailing list says repo
URL and branch name alone. This is designed to be easily cut&pasted to
"git fetch" command line:
Linus, please pull from
git://git..../proj.git master
to get the following updates...
becomes:
$ git pull git://git..../proj.git master
In such a case, you do not want to automatically follow other's tags.
One important aspect of git is it is distributed, and being distributed
largely means there is no inherent "upstream" or "downstream" in the
system. On the face of it, the above example might seem to indicate
that the tag namespace is owned by upper echelon of people and tags
only flow downwards, but that is not the case. It only shows that the
usage pattern determines who are interested in whose tags.
A one-shot pull is a sign that a commit history is now crossing the
boundary between one circle of people (e.g. "people who are primarily
interested in networking part of the kernel") who may have their own
set of tags (e.g. "this is the third release candidate from the
networking group to be proposed for general consumption with 2.6.21
release") to another circle of people (e.g. "people who integrate
various subsystem improvements"). The latter are usually not interested
in the detailed tags used internally in the former group (that is what
"internal" means). That is why it is desirable not to follow tags
automatically in this case.
It may well be that among networking people, they may want to exchange
the tags internal to their group, but in that workflow they are most
likely tracking with each other's progress by having tracking branches.
Again, the heuristic to automatically follow such tags is a good thing.
On Backdating Tags
If you have imported some changes from another VCS and would like to
add tags for major releases of your work, it is useful to be able to
specify the date to embed inside of the tag object. The data in the tag
object affects, for example, the ordering of tags in the gitweb
interface.
To set the date used in future tag objects, set the environment
variable GIT_COMMITTER_DATE to one or more of the date and time. The
date and time can be specified in a number of ways; the most common is
"YYYY-MM-DD HH:MM".
An example follows.
$ GIT_COMMITTER_DATE="2006-10-02 10:31" git tag -s v1.0.1
AUTHOR
Written by Linus Torvalds <torvalds@osdl.org>, Junio C Hamano
<junkio@cox.net> and Chris Wright <chrisw@osdl.org>.
DOCUMENTATION
Documentation by David Greaves, Junio C Hamano and the git-list
<git@vger.kernel.org>.
GIT
Part of the git(7) suite
Git 1.5.5.2 10/21/2008 GIT-TAG(1)
