You hear that issue FOO-123 has been fixed. The bug had something to do with a subsystem you know well, so you have your own hunch about what might have caused it. To confirm your suspicion, you decide to take a look at how the bug was fixed. You spend quite some time rummaging through the revision history until you manage to narrow the fix down to four consecutive revisions, described in their commit messages as "dao tweaks", "moar", "Fixes." and "remove debug stuff". Each changeset looks huge.