Release guide#

This document is only relevant for Matplotlib release managers.

A guide for developers who are doing a Matplotlib release.

Versioning Scheme#

Maplotlib follows the Intended Effort Versioning (EffVer) versioning scheme: macro.meso.micro.

macro

A release that we expect a large effort from our users to upgrade to. The v1 to v2 transition included a complete overhaul of the default styles and the v2 to v3 transition involved dropping support for Python 2.

Future macro versions would include changes of a comparable scale that can not be done incrementally in meso releases.

meso

A release that we expect some effort from our users to upgrade to. We target a Meso release every 6 months. These release are primarily intended to release new features to our users, however they also contain intentional feature deprecations and removals per our policy.

micro

A release that we expect users to require little to no effort to upgrade to. Per our Backport strategy we only backport bug fixes to the maintenance branch. We expect minimal impact on users other than possibly breaking work arounds to a fixed bug or bugs being used as features.

These are released as-needed, but typically every 1-2 months between meso releases.

Making the release branch#

Note

This assumes that a read-only remote for the canonical repository is remote and a read/write remote is DANGER

When a new meso release (vX.Y.0) is approaching, a new release branch must be made. When precisely this should happen is up to the release manager, but this point is where most new features intended for the meso release are merged and you are entering a feature freeze (i.e. newly implemented features will be going into vX.Y+1). This does not necessarily mean that no further changes will be made prior to release, just that those changes will be made using the backport system.

For an upcoming v3.7.0 release, first create the branch:

git switch main
git pull
git switch -c v3.7.x
git push DANGER v3.7.x

Update the v3.7.0 milestone so that the description reads:

New features and API changes

on-merge: backport to v3.7.x

Micro versions should instead read:

Bugfixes and docstring changes

on-merge: backport to v3.7.x

Check all active milestones for consistency. Older milestones should also backport to higher meso versions (e.g. v3.6.3 and v3.6-doc should backport to both v3.6.x and v3.7.x once the v3.7.x branch exists and while PR backports are still targeting v3.6.x)

Create the milestone for the next-next meso release (i.e. v3.9.0, as v3.8.0 should already exist). While most active items should go in the next meso release, this milestone can help with longer term planning, especially around deprecation cycles.

Testing#

We use GitHub Actions for continuous integration. When preparing for a release, the final tagged commit should be tested locally before it is uploaded:

pytest -n 8 .

In addition the following test should be run and manually inspected:

python tools/memleak.py agg 1000 agg.pdf

Run the User Acceptance Tests for the NBAgg and ipympl backends:

jupyter notebook lib/matplotlib/backends/web_backend/nbagg_uat.ipynb

For ipympl, restart the kernel, add a cell for %matplotlib widget and do not run the cell with matplotlib.use('nbagg'). Tests which check connection_info, use reshow, or test the OO interface are not expected to work for ipympl.

GitHub statistics#

We automatically extract GitHub issue, PRs, and authors from GitHub via the API. To prepare this list:

  1. Archive the existing GitHub statistics page.

    1. Copy the current doc/users/github_stats.rst to doc/users/prev_whats_new/github_stats_X.Y.Z.rst.

    2. Change the link target at the top of the file.

    3. Remove the "Previous GitHub Stats" section at the end.

    For example, when updating from v3.7.0 to v3.7.1:

    cp doc/users/github_stats.rst doc/users/prev_whats_new/github_stats_3.7.0.rst
    $EDITOR doc/users/prev_whats_new/github_stats_3.7.0.rst
    # Change contents as noted above.
    git add doc/users/prev_whats_new/github_stats_3.7.0.rst
    
  2. Re-generate the updated stats:

    python tools/github_stats.py --since-tag v3.7.0 --milestone=v3.7.1 \
        --project 'matplotlib/matplotlib' --links > doc/users/github_stats.rst
    
  3. Review and commit changes. Some issue/PR titles may not be valid reST (the most common issue is * which is interpreted as unclosed markup).

Note

Make sure you authenticate against the GitHub API. If you do not, you will get blocked by GitHub for going over the API rate limits. You can authenticate in one of two ways:

  • using the keyring package; pip install keyring and then when running the stats script, you will be prompted for user name and password, that will be stored in your system keyring, or,

  • using a personal access token; generate a new token on this GitHub page with the repo:public_repo scope and place the token in ~/.ghoauth.

Update and validate the docs#

Merge *-doc branch#

Merge the most recent 'doc' branch (e.g., v3.7.0-doc) into the branch you are going to tag on and delete the doc branch on GitHub.

Update supported versions in Security Policy#

When making macro or meso releases, update the supported versions in the Security Policy in SECURITY.md.

For meso version release update the table in SECURITY.md to specify that the two most recent meso releases in the current macro version series are supported.

For a macro version release update the table in SECURITY.md to specify that the last meso version in the previous macro version series is still supported. Dropping support for the last version of a macro version series will be handled on an ad-hoc basis.

Update release notes#

What's new#

Only needed for macro and meso releases. Bugfix releases should not have new features.

Merge the contents of all the files in doc/users/next_whats_new/ into a single file doc/users/prev_whats_new/whats_new_X.Y.0.rst and delete the individual files.

API changes#

Primarily needed for macro and meso releases. We may sometimes have API changes in micro releases.

Merge the contents of all the files in doc/api/next_api_changes/ into a single file doc/api/prev_api_changes/api_changes_X.Y.Z.rst and delete the individual files.

Release notes TOC#

Update doc/users/release_notes.rst:

  • For macro and meso releases add a new section

    X.Y
    ===
    .. toctree::
        :maxdepth: 1
    
        prev_whats_new/whats_new_X.Y.0.rst
        ../api/prev_api_changes/api_changes_X.Y.0.rst
        prev_whats_new/github_stats_X.Y.0.rst
    
  • For micro releases add the GitHub stats and (if present) the API changes to the existing X.Y section

    ../api/prev_api_changes/api_changes_X.Y.Z.rst
    prev_whats_new/github_stats_X.Y.Z.rst
    

Update version switcher#

Update doc/_static/switcher.json:

  • If a micro release, X.Y.Z, no changes are needed.

  • If a macro release, X.Y.0, change the name of name: X.Y+1 (dev) and name: X.Y (stable) as well as adding a new version for the previous stable (name: X.Y-1).

Verify that docs build#

Finally, make sure that the docs build cleanly:

make -Cdoc O=-j$(nproc) html latexpdf

After the docs are built, check that all of the links, internal and external, are still valid. We use linkchecker for this:

pip install linkchecker
pushd doc/build/html
linkchecker index.html --check-extern
popd

Address any issues which may arise. The internal links are checked on Circle CI, so this should only flag failed external links.

Create release commit and tag#

To create the tag, first create an empty commit with a very terse set of the release notes in the commit message:

git commit --allow-empty

and then create a signed, annotated tag with the same text in the body message:

git tag -a -s v3.7.0

which will prompt you for your GPG key password and an annotation. For pre-releases it is important to follow PEP 440 so that the build artifacts will sort correctly in PyPI.

To prevent issues with any down-stream builders which download the tarball from GitHub it is important to move all branches away from the commit with the tag [1]:

git commit --allow-empty

Finally, push the tag to GitHub:

git push DANGER v3.7.x v3.7.0

Congratulations, the scariest part is done! This assumes the release branch has already been made. Usually this is done at the time of feature freeze for a meso release (which often coincides with the last micro release of the previous meso version)

If this is a final release, also create a 'doc' branch (this is not done for pre-releases):

git branch v3.7.0-doc
git push DANGER v3.7.0-doc

Update (or create) the v3.7-doc milestone. The description should include the instruction for meeseeksmachine to backport changes with the v3.7-doc milestone to both the v3.7.x branch and the v3.7.0-doc branch:

Documentation changes (.rst files and examples)

on-merge: backport to v3.7.x
on-merge: backport to v3.7.0-doc

Check all active milestones for consistency. Older doc milestones should also backport to higher meso versions (e.g. v3.6-doc should backport to both v3.6.x and v3.7.x if the v3.7.x branch exists)

Release management / DOI#

Via the GitHub UI, turn the newly pushed tag into a release. If this is a pre-release remember to mark it as such.

For final releases, also get the DOI from Zenodo (which will automatically produce one once the tag is pushed). Add the DOI post-fix and version to the dictionary in tools/cache_zenodo_svg.py and run the script.

This will download the new SVG to doc/_static/zenodo_cache/postfix.svg and edit doc/project/citing.rst. Commit the new SVG, the change to tools/cache_zenodo_svg.py, and the changes to doc/project/citing.rst to the VER-doc branch and push to GitHub.

git checkout v3.7.0-doc
$EDITOR tools/cache_zenodo_svg.py
python tools/cache_zenodo_svg.py
git commit -a
git push DANGER v3.7.0-doc:v3.7.0-doc

Building binaries#

We distribute macOS, Windows, and many Linux wheels as well as a source tarball via PyPI. Most builders should trigger automatically once the tag is pushed to GitHub:

  • Windows, macOS and manylinux wheels are built on GitHub Actions. Builds are triggered by the GitHub Action defined in .github/workflows/cibuildwheel.yml, and wheels will be available as artifacts of the build.

  • The auto-tick bot should open a pull request into the conda-forge feedstock. Review and merge (if you have the power to).

Warning

Because this is automated, it is extremely important to bump all branches away from the tag as discussed in Create release commit and tag.

Make distribution and upload to PyPI#

Once you have collected all of the wheels (expect this to take a few hours), generate the tarball:

git checkout v3.7.0
git clean -xfd
python -m build --sdist

and copy all of the wheels into dist directory. First, check that the dist files are OK:

twine check dist/*

and then use twine to upload all of the files to PyPI

twine upload -s dist/matplotlib*tar.gz
twine upload dist/*whl

Congratulations, you have now done the second scariest part!

Build and deploy documentation#

To build the documentation you must have the tagged version installed, but build the docs from the ver-doc branch. An easy way to arrange this is:

pip install matplotlib
pip install -r requirements/doc/doc-requirements.txt
git checkout v3.7.0-doc
git clean -xfd
make -Cdoc O="-t release -j$(nproc)" html latexpdf LATEXMKOPTS="-silent -f"

which will build both the HTML and PDF version of the documentation.

The built documentation exists in the matplotlib.github.com repository. Pushing changes to main automatically updates the website.

The documentation is organized in subdirectories by version. The latest stable release is symlinked from the stable directory. The documentation for current main is built on Circle CI and pushed to the devdocs repository. These are available at matplotlib.org/devdocs.

Assuming you have this repository checked out in the same directory as matplotlib

cd ../matplotlib.github.com
cp -a ../matplotlib/doc/build/html 3.7.0
rm 3.7.0/.buildinfo
cp ../matplotlib/doc/build/latex/Matplotlib.pdf 3.7.0

which will copy the built docs over. If this is a final release, link the stable subdirectory to the newest version:

rm stable
ln -s 3.7.0 stable

You will need to manually edit versions.html to show the released version. You will also need to edit sitemap.xml to include the newly released version. Now commit and push everything to GitHub

git add *
git commit -a -m 'Updating docs for v3.7.0'
git push DANGER main

Congratulations you have now done the third scariest part!

If you have access, clear the CloudFlare caches.

It typically takes about 5-10 minutes for the website to process the push and update the live web page (remember to clear your browser cache).

Merge up changes to main#

After a release is done, the changes from the release branch should be merged into the main branch. This is primarily done so that the released tag is on the main branch so git describe (and thus setuptools-scm) has the most current tag. Secondarily, changes made during release (including removing individualized release notes, fixing broken links, and updating the version switcher) are bubbled up to main.

Git conflicts are very likely to arise, though aside from changes made directly to the release branch (mostly as part of the release), they should be relatively-easily resolved by using the version from main. This is not a universal rule, and care should be taken to ensure correctness:

git switch main
git pull
git switch -c merge_up_v3.7.0
git merge v3.7.x
# resolve conflicts
git merge --continue

Due to branch protections for the main branch, this is merged via a standard pull request, though the PR cleanliness status check is expected to fail. The PR should not be squashed because the intent is to merge the branch histories.

Publicize this release#

After the release is published to PyPI and conda, it should be announced through our communication channels:

Conda packages#

The Matplotlib project itself does not release conda packages. In particular, the Matplotlib release manager is not responsible for conda packaging.

For information on the packaging of Matplotlib for conda-forge see conda-forge/matplotlib-feedstock.