Release guide

This guide documents napari’s release process. Currently, it only handles distribution, but as the project matures, it will include generating release notes, documentation, etc.

This is mainly meant for the core developers who will actually be performing the release. They will need to have a PyPI account with upload permissions to the napari package.

You will also need the additional release dependencies (pip install -e .[release]) to complete the release process. determines which non-Python files are included. Make sure to check that all necessary ones are listed before beginning the release process.

The napari/napari repository must have a PyPI API token as a GitHub secret. This likely has been done already, but if it has not, follow this guide to gain a token and this guide to add it as a secret.

Determining the version

The version of napari is automatically determined at install time by setuptools_scm from the latest git tag beginning with v. Thus, you’ll need to tag the reference with the new version number. It is likely something like X.Y.Z. Before making a release though we need to generate the release notes.

Generating release notes

  1. Make a list of merges, contributors, and reviewers by running python docs/release/ -h and following that file’s usage. For each release generate the list to include everything since the last release for which there are release notes (which should just be the last release). For example making the release notes for the 0.2.1 release can be done as follows:

    python docs/release/ v0.2.0 main --version 0.2.1 | tee docs/release/
  2. Scan the PR titles for highlights, deprecations, API changes, and bugfixes, and mention these in the relevant sections of the notes. Try to present the information in an expressive way by mentioning the affected functions, elaborating on the changes and their consequences. If possible, organize semantically close PRs in groups.

  3. Make sure the file name is of the form doc/release/release_<major>_<minor>_<release>.md.

  4. Make and merge a PR with these release notes before moving onto the next steps.

Update translation strings

As new code is included in the codebase, some of the strings that need to be translated might not yet be using the trans methods. To help keep the codebase up to date in terms of translations we added a test script that runs daily on CI and can be also run locally to ensure that a release includes the most up to date translatable strings.

The test script is available on the /tools/ file and it relies on an additional file /tools/ to include strings to skip safely from translation.

The test checks:

  1. Untranslated strings: not using the trans methods.

  2. Outdated skip strings: should no longer be included in the /tools/ file.

  3. Translation usage errors: where translation strings may be missing interpolation variables.

You can execute tests locally from the repository root, and follow the instructions printed on the stdout if any test fails.

pytest tools/ --tb=short

Tagging the new release candidate

First we will generate a release candidate, which will contain the letters rc. Using release candidates allows us to test releases on PyPI without using up the actual release number.

You can tag the current source code as a release candidate with:

git tag vX.Y.Zrc1 main

If the tag is meant for a previous version of main, simply reference the specific commit:

git tag vX.Y.Zrc1 abcde42

Note here how we are using rc for release candidate to create a version of our release we can test before making the real release.

You can read more on tagging here.

Testing the release candidate

Our CI automatically makes a release, copying the release notes to the tag and uploading the distribution to PyPI. You can trigger this by pushing the new tag to napari/napari:

git push upstream --tags

The release candidate can then be tested with

pip install --pre napari

It is recommended that the release candidate is tested in a virtual environment in order to isolate dependencies.

If the release candidate is not what you want, make your changes and repeat the process from the beginning but incrementing the number after rc on tag (e.g. vX.Y.Zrc2).

Once you are satisfied with the release candidate it is time to generate the actual release.

Generating the actual release

To generate the actual release you will now repeat the processes above but now dropping the rc. For example:

git tag vX.Y.Z main
git push upstream --tags