What to do if what you need to fix is in the published part of the history? As described in Perils of rewriting published history section, changing the parts of the history that were made public (which is actually creating a changed copy and replacing references) can cause problems for downstream developers. You better not to touch this part of the graph of revisions.

There are a few solutions to this problem. The most commonly used is to put a new fixup commit with appropriate changes (for example, a typo fix in a documentation). If you need to remove changes, deciding that they turned out to be bad to have, you can create a commit to revert the changes.

If you fix a commit or revert one, it would be nice to annotate that commit with the information that it was buggy, and which commit fixed (or reverted) it. Even though you cannot (should not) edit the fixed commit to add this information if the commit is public, Git provides a notes mechanism to append...