Bug trackers
============

Bazaar has a facility that allows you to associate a commit with a bug
in the project's bug tracker. Other tools (or hooks) can then use this
information to generate hyperlinks between the commit and the bug, or to
automatically mark the bug closed in the branches that contain the commit.

Associating commits and bugs
----------------------------

When you make a commit, you can associate it with a bug by using the
``--fixes`` option of ``commit``. For example::

    $ bzr commit --fixes lp:12345 -m "Properly close the connection"

This records metadata in Bazaar linking the commit with bug 12345 in
Launchpad. If you use a different bug tracker, it can be given its own
tracker code (instead of ``lp``) and used instead. For details on how
to configure this for Bugzilla, Trac, Roundup and other bug/issue trackers,
refer to `Bug Tracker Settings`_ in the Bazaar User Reference.

.. _Bug Tracker Settings: ../user-reference/bzr_man.html#bug-tracker-settings

Metadata recording vs bug tracker updating
------------------------------------------

Recording metadata about bugs fixed at commit time is only
one of the features needed for complete bug tracker integration.
As Bazaar is a distributed VCS, users may be offline while committing
so accessing the bug tracker itself at that time may not be possible.
Instead, it is recommended that a hook be installed to update
the bug tracker when changes are pushed to a central location
appropriate for your project's workflow.

Note: This second processing stage is part of the integration provided
by Launchpad when it scans external or hosted branches.

Making corrections
------------------

This method of associating revisions and bugs does have some limitations. The
first is that the association can only be made at commit time. This means that
if you forget to make the association when you commit, or the bug is reported
after you fix it, you generally cannot go back and add the link later.

Related to this is the fact that the association is immutable. If a bug is
marked as fixed by one commit but that revision does not fully solve the
bug, or there is a later regression, you cannot go back and remove the link.

Of course, ``bzr uncommit`` can always be used to undo the last commit in
order to make it again with the correct options. This is commonly done
to correct a bad commit message and it equally applies to correcting
metadata recorded (via ``--fixes`` for example) on the last commit.

Note: ``uncommit`` is best done before incorrect revisions become public.
