How to make a new release of ``skimage``
========================================

While following this guide, note down all the times that you need to
consult a previous release manager, or that you find an instruction
unclear. You will, of course, make a PR to update these notes after
you are done with the release! ;-)

Before you start, make sure you have all the required write
permissions (if not, you will need to ask an owner to grant you
access), specifically to:

  - https://pypi.org/project/scikit-image/
  - https://github.com/scikit-image/skimage-web


- Check ``TODO.txt`` for any outstanding tasks.

We use a variant of "semantic versioning", where version numbers are classified
as v<major>.<minor>.<patch>.  By default, releases are made from the main
branch as part of a linear release history and, as described below, are
triggered by pushing a git tag to the scikit-image repository on github.  If
a patch release is required, a branch can be created from the appropriate point
in main and the following instructions are still apt.

Example `version number`

- 0.23.0rc0.dev0  # development version for 0.23.0 first release candidate
- 0.23.0rc0       # 0.23.0 first release candidate
- 0.23.0rc1.dev0  # development version for 0.23.0 second release candidate
- 0.23.0          # 0.23.0 release
- 0.24.0rc0.dev0  # development version for 0.24.0 first release candidate

## Process

- To debug building and testing wheels via CI, push to a branch named
  `maintenance/anything`.

  Once everything works as intended, remove those branches and proceed.

- Set release variables:

      export VERSION=<version number>
      export PREVIOUS=<previous version number>
      export ORG="scikit-image"
      export REPO="scikit-image"

  If this is a prerelease:

      export NOTES="doc/source/release_notes/release_dev.rst"

  If this is release:

      export NOTES="doc/source/release_notes/release_${VERSION}.rst"
      git rm doc/source/release_notes/release_dev.rst

- Autogenerate release notes:

      changelist ${ORG}/${REPO} v${PREVIOUS} main --version ${VERSION}  --out ${NOTES} --format rst
      changelist ${ORG}/${REPO} v${PREVIOUS} main --version ${VERSION}  --out ${VERSION}.md

- If you want, you can review the release notes:

  - Scan the PR titles for highlights and mention these in the
    relevant sections of the notes.
    Ideally, all changed API objects are mentioned by name,
    e.g. a new parameter or a deprecated function.

  - Check for duplicate names in the automatically generated list of
    contributors and reviewers.

  - Append the release date to the title similar to previous iterations.

- If this is a release:

  - (Only needed if you create a new branch)
    update the file ``skimage/data/_fetchers.py`` to point the pooch
    repository to the new branch instead of main during testing.
    Look for the parameter ``version_dev="main",`` for ``pooch.create`` and
    change it to the newly created branch name.

  - Edit ``doc/source/_static/docversions.js`` and
    ``doc/source/_static/version_switcher.json`` in order to add the release, move the
    key value pair `"preferred": true` to the most recent stable version, and commit.

      git add skimage/data/_fetchers.py doc/source/_static/docversions.js doc/source/_static/version_switcher.json

- Update ``__version__`` in ``skimage/__init__.py``.

- Commit changes:

      git add skimage/__init__.py ${NOTES}
      git commit -m "Designate ${VERSION} release"

- Tag the release in git:

      git tag -s v${VERSION} -m "signed ${VERSION} tag"

  (If you do not have a GPG key, follow the tutorial to set it up:
   https://help.github.com/articles/signing-commits-with-gpg/)

- Push the new meta-data to github:

      git push --tags origin main

  where `origin` is the name of the ``github.com:scikit-image/scikit-image``
  repository

- Create release from tag

      - go to https://github.com/scikit-image/scikit-image/releases/new?tag=v${VERSION}
      - add v${VERSION} for the `Release title`
      - paste contents (or upload) of ${VERSION}.md in the `Describe this release section`
      - if pre-release check the box labelled `Set as a pre-release`

- Update https://github.com/scikit-image/scikit-image/milestones:

      - close old milestone
      - ensure new milestone exists (perhaps setting due date)

- Update ``__version__`` in ``skimage/__init__.py``.

- Commit changes:

      git add skimage/__init__.py
      git commit -m 'Bump version'
      git push origin main

- Update documentation on the web:
  The documentation is kept in a separate repo: scikit-image/docs

  - Wait for the CI service to deploy to GitHub Pages
  - Sync your branch with the remote repo: ``git pull``.
  - Update the docs

      git switch gh-pages
      git branch -C gh-pages gh-pages-backup
      cp -a dev ../.
      git reset --hard <commit from last release>
      git rm -rf dev
      cp -a ../dev .
      git add dev
      cp -a ../dev <release name, e.g., 0.23.x>
      git add <release name, e.g., 0.23.x>
      rm stable
      ln -s <release name, e.g., 0.23.x> stable
      git add stable
      git commit -m "Add <release name, e.g., 0.23.x>"
      git push -f origin gh-pages # force push---be careful!

- Update the web frontpage:
  The webpage is kept in a separate repo: scikit-image/skimage-web

  - Highlight new release in the news section

      git pull
      # Edit the ``News`` section of ``index.rst``
      git add index.rst
      git commit -m "Highlight ${VERSION} release"
      git push

----

- Post release notes on user & dev forums, blog, Twitter, etc.

  - https://forum.image.sc/tag/scikit-image
  - https://discuss.scientific-python.org/c/contributor/skimage
  - scipy-user@python.org
  - scikit-learn@python.org

- Update the version and the release date on Wikipedia
  https://en.wikipedia.org/wiki/Scikit-image

- Make a PR to scikit-image with any updates you might have to these notes

- If making a patch release (v<major>.<minor>.<patch>), forward-port the
  release notes to the main branch and make a PR.

Conda-forge
-----------

**Note**: conda-forge now has an automated bot who makes the below PR for you.
Now all you have to do is to look at pull requests at
https://github.com/conda-forge/scikit-image-feedstock/pulls
and check for a new one for this version. Wait for all the continuous
integration checks to go green, then merge.

The manual instructions remain below in case the bot fails for some reason.

A scikit-image build recipe resides at
https://github.com/conda-forge/scikit-image-feedstock. You should update it to
point to the most recent release. You can do this by following these steps:

- Fork the repository at https://github.com/conda-forge/scikit-image-feedstock,
  and clone it to your machine.
- Sprout a new branch, e.g. ``v<major>.<minor>``.
- Find out the SHA256 hash of the source distribution. You can find this at
  https://pypi.org/project/scikit-image/, or use the following commands:

  - ``sha256sum path/to/scikit-image-*.tar.gz`` (Linux)
  - ``shasum -a 256 dist/scikit-image-*.tar.gz`` (macOS)
  - ``CertUtil -hashfile dist\scikit-image-*.tar.gz SHA256`` (Windows)

- Edit the file ``recipe/meta.yaml``:

  - Update the version number on the first line.
  - Update the SHA256 value on line 9.
  - If necessary, reset the build number to 0. (line 12)
  - Update any requirements in the appropriate sections (build or run).
    Note: don't remove ``numpy x.x``. This tells conda-smithy, conda-forge's
    build system, that the library must be linked against NumPy at build time.
  - Commit these changes.
  - Update the infrastructure around the recipe with ``conda-smithy``:
    * Install conda-smithy either with conda or pip
    * Run ``conda-smithy rerender`` in the root of the repository, and commit
      the changes.

- Push to your fork, and submit a pull request to the
  upstream repo.

Debian
------

The below instructions remain here for completeness. However, the Debian
scientific team has kindly taken over package maintenance. Simply follow the
procedure described at https://www.debian.org/Bugs/Reporting to report a "bug"
that there is a new version of scikit-image out (specifying the version
number), with severity set to "Wishlist".

If you want to take matters into your own hands for some reason, follow the
instructions detailed below to cut a Debian release yourself.

- Tag the release as per instructions above.
- git checkout debian
- git merge v0.x.x
- uscan <- not sure if this step is necessary
- Update changelog (emacs has a good mode, requires package dpkg-dev-el)
  - C-C C-v add new version, C-c C-c timestamp / save
- git commit -m 'Changelog entry for 0.x.x'
- git-buildpackage -uc -us -rfakeroot
- Sign the changes: debsign skimage_0.x.x-x_amd64.changes
- cd ../build-area && dput mentors skimage_0.x.x-x_amd64.changes
- The package should now be available at:

  http://mentors.debian.net/package/skimage

For the last lines above to work, you need ``~/.gbp.conf``::

  [DEFAULT]
  upstream-tag = %(version)s

  [git-buildpackage]
  sign-tags = True
  export-dir = ../build-area/
  tarball-dir = ../tarballs/

As well as ``~/dput.cf``::

  [mentors]
  fqdn = mentors.debian.net
  incoming = /upload
  method = http
  allow_unsigned_uploads = 0
  progress_indicator = 2
  # Allow uploads for UNRELEASED packages
  allowed_distributions = .*
