Documenting Changes

When you change bzr, please update the relevant documentation for the change you made:

Changing existing behavior

If the change will break existing command lines, or break interoperability with other versions of Breezy, mention this in “External Compatibility Breaks” in NEWS, and also in “What’s New”.

Adding a new feature, function or option

Describe this in NEWS, in the user guide, and in the “What’s New” document. Consider whether you should also update command help or any help topics.

A new hook or extension point

These are also described in NEWS, in the hook documentation, and in “What’s New.” Even though they might be API-only changes, the fact that they exist may interest users enough to write a new plugin that uses them.

Fixing a bug

If the bug has any user-visible impact, describe it in the NEWS file in such a way that users can tell whether the problem they’re experiencing is the one that was fixed.

Improving performance

Mention this under “improvements” in NEWS, and if it’s a notable improvement mention it in “What’s New”.

Deprecating an API, or adding a new recommended API

Mention this in the “API Changes” of NEWS, if it’s likely to affect plugin authors. Consider whether you should also update the developer documentation.

Changing the way the test suite works or adding more tests

Mention this under “Testing” in NEWS, and update the developer guide to testing.

Purely internal changes

If the change has no user-visible impact and is not interesting to plugin developers, it doesn’t need to be mentioned in NEWS. If you’re setting a new pattern or adding a new abstraction, update the developer docs.


If you make a user-visible change, please add a note to the NEWS file. The description should be written to make sense to someone who’s just a user of bzr, not a developer: new functions or classes shouldn’t be mentioned, but new commands, changes in behaviour or fixed nontrivial bugs should be listed. See the existing entries for an idea of what should be done.

Within each release, entries in the news file should have the most user-visible changes first. So the order should be approximately:

  • changes to existing behaviour - the highest priority because the user’s existing knowledge is incorrect

  • new features - should be brought to their attention

  • bug fixes - may be of interest if the bug was affecting them, and should include the bug number if any

  • major documentation changes, including fixed documentation bugs

People who made significant contributions to each change are listed in parenthesis. This can include reporting bugs (particularly with good details or reproduction recipes), submitting patches, etc.

To help with merging, NEWS entries should be sorted lexicographically within each section.


The docstring of a command is used by bzr help to generate help output for the command. The list ‘takes_options’ attribute on a command is used by bzr help to document the options for the command - the command docstring does not need to document them. Finally, the ‘_see_also’ attribute on a command can be used to reference other related help topics.

API Documentation

Functions, methods, classes and modules should have docstrings describing how they are used.

The first line of the docstring should be a self-contained sentence.

For the special case of Command classes, this acts as the user-visible documentation shown by the help command.

The docstrings should be formatted as reStructuredText (like this document), suitable for processing using the epydoc tool into HTML documentation.