A good commit message makes reviewing your changes later easier, and is especially helpful when the release wrangler is ensuring that the version history is complete.

A commit message should have:

*:The GitTrac ticket number, in the form #123.  Note that you cannot have a "#" at the start of a line; Git will think it's a comment.  Common techniques include putting the comment at the end of the line, or enclosing it in parenthesis like (#123).  If multiple tickets are involved, feel free to list them all.  If zero tickets are involved, consider creating a ticket so people have a place to discuss the change and a convenient place to point to for all relevant information.
*:: Why? This number makes correlating the version history easier (assuming you include the ticket number in a comment in the version history like you should).  It also means that the ticket can include links to the relevant commits.

*:A brief description of what you changed.

*:Optionally, some extended discussion on what you changed, if you think it useful.

*:Finally, if you are confident that this change should not be mentioned in the version history, a brief note explaining why.  Is it entirely invisible to the user (internal cleanup)?  Does it fix a bug that was never released?

Finally, *remember to update the Version History!* VersionHistoryHowTo

{subsection: Git help for tickets}

You may be absent-minded, and everyone occasionally forgets to put ticket numbers in their commit message. Git will actually help with this.  You can run the following commands:
{code}
git config --global commit.template ~/.gittemplate
{endcode}
Then, edit your =~/.gittemplate= file to look like the following:
{code}
The ticket is #xxxx
{endcode}
This template will be included in your commit message every time you run "=git commit=", and reminds you to write a ticket number.

Sometimes you will be in a hurry, and rush over the ticket number above. For this situation, you can install the following executable script at =<path-to-CONDOR_SRC>/.git/hooks/commit-msg=:

{code}
#!/bin/sh
#
# An example hook script to check the commit log message.
# Called by git-commit with one argument, the name of the file
# that has the commit message.  The hook should exit with non-zero
# status after issuing an appropriate message if it wants to stop the
# commit.  The hook is allowed to edit the commit message file.

/bin/grep -E -q '\#[0-9]+' "$1" || {
        echo
        echo
        echo "****** YOUR COMMIT WAS NOT ACCEPTED ******"
        echo "You need to assign a ticket number"
        echo
        echo
        exit 1
}
{endcode}

So now git will remind you loudly and refuse to commit if you forget to include a ticket number.  If you are really sure that a ticket is not needed, you can override this with the command =git commit --no-verify=.