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.
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.
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.
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.