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! ;-)

Some of the instructions don't apply to patch releases. As a reminder, we use a
variant of "semantic versioning", where version numbers are classified as
v<major>.<minor>.<patch>. If you are making a patch release, skip the first
three steps. Instead, make a PR to update ``release_<major>.<minor>.txt`` on
the corresponding release branch.

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


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

- Branch v<major>.<minor>.x from master. This is the "release branch", where
  you will make your changes gearing up for release, and cherry-pick them as
  appropriate to master.

- On the release branch, update the release notes:

  1. Review and cleanup ``doc/release/release_dev.rst``.

  2. Make a list of merges, contributors, and reviewers by running
     ``tools/generate_release_notes.py -h`` and following that file's usage.

  3. Paste this list at the end of the ``release_dev.txt``.

  4. 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.

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

  6. Rename the file to ``doc/release/release_<major>.<minor>.txt``

  7. Copy ``doc/release/release_template.txt`` to
     ``doc/release/release_dev.txt`` for the next release.

  8. Copy relevant deprecations from ``release_<major>_<minor>.txt``
     to ``release_dev.txt``.

- Submit the release notes for review by other project maintainers:

  - Create a PR from v<major>.<minor>.x branch to master (at this point,
    the difference should show the full contents of the release notes).
  - Discuss with others, and make the changes directly to v<major>.<minor>.x branch.
  - Once the consensus is found, ask the project maintainers to merge
    the PR.
  - Cherry pick the change onto the release branch.

- On the master branch, update the version number in ``skimage/__init__.py``
  to the next ``.dev0`` version, commit, and push. This should follow PEP440
  meaning that the appropriate version number would look something like
  ``0.20.dev0`` with the period between ``20`` and ``dev`` and a trailing
  ``0`` immediately after ``dev``.

- On the master branch, edit ``doc/source/_static/docversions.js``,
  add the release, e.g., `0.15.x`, and commit.  Cherry-pick this
  change back to the release branch.

- Back on the release branch, update the version number to match the release
  version in ``skimage/__init__.py``, commit, and push.

- Update the release docs:

  - On the release branch, build a clean version of the docs. In the
    root directory, run ``pip install .``.
  - In the ``doc/`` directory:
    - Build using
      ``make clean; make html; make gh-pages``.
    - Check (since this a new feature) that binder links in gallery examples
      point to the release branch, e.g. `0.16.x`.
    - In the ``gh-pages/`` directory:
      - Update the symlink to ``stable`` and commit.
      - Upload the docs: ``git push origin gh-pages``.

At this point, you are ready to tag the new version.  This "seals the
deal", so we want to make sure everything is working.  Go to
https://travis-ci.org/scikit-image/scikit-image/branches, click on the
release branch, and ensure that all checks have passed for the latest
build.  Do the same for AppVeyor at
https://ci.appveyor.com/project/scikit-image/scikit-image/history.

Now, build a trial version of the binary wheels we will be shipping:

  - Clone https://github.com/scikit-image/scikit-image-wheels.
  - Switch to the appropriate v<major>.<minor>.x branch.
  - Update its ``.travis.yml`` file so that ``BUILD_COMMIT`` points to this
    branch (e.g. ``v0.16.x``).
  - Update its ``.appveyor.yml`` file so that ``BUILD_COMMIT`` also points to
    this release tag.
  - Commit and push.
  - Monitor the builds at
    https://ci.appveyor.com/project/scikit-image/scikit-image-wheels and
    https://travis-ci.org/scikit-image/scikit-image-wheels/branches
  - When all is green, spot-check a couple of builds to make sure that the
    wheels have correctly uploaded. You should see a message like:
    ``python -m wheelhouse_uploader upload --local-folder``, with output:
    ``Wheelhouse successfully published at:
    http://[crazyrandomstring].rackcdn.com``
  - Open that URL and check for the wheels as
    ``scikit_image-<versiontag>-<platforminfo>.whl``

**Do not tag until the builds are all green.**

- Add the version number as a tag in git::

   git tag -s -m <github_release_message> [-u <key-id>] v<major>.<minor>.0

  (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 tag to GitHub::

   git push upstream v<major>.<minor>.0

  (where ``upstream`` is the name of the
   ``github.com:scikit-image/scikit-image`` repository.)

- Build the package wheels again, but change BUILD_COMMIT in both
  Travis-CI and AppVeyor to the release version, e.g., ``v0.16.0``.

- Upload the wheels to PyPI:

  - Make sure ``twine`` is available. You can install it with
    ``pip install twine``.
  - Download ``wheel-uploader`` [1]_ and place it on your PATH.
  - Run ``tools/upload_wheels.sh``.
  - If everything worked, delete the wheels from your local directory with
    ``rm -rf *.whl``

.. [1] https://github.com/MacPython/terryfy/blob/master/wheel-uploader

- Publish the source distribution on PyPi::

   python setup.py sdist
   twine upload dist/scikit-image-<major>.<minor>.0.tar.gz

- Update the web frontpage:
  The webpage source is kept in a separate repo: scikit-image-web. The
  live webpage lives in a second repo, scikit-image.github.com, that you only
  interact with via the ``make`` command within scikit-image-web.

  - Sync your branch with the remote repo: ``git pull``.
    If you try to ``make gh-pages`` when your branch is out of sync, it
    creates headaches.
  - Add release date to ``index.rst`` under "News".
  - Add previous stable version documentation path to disallowed paths
    in `robots.txt`
  - Commit and push back to master. (Nothing is being served at this stage.)
  - Build using ``make gh-pages``. (This checks out a copy of the
    scikit-image.github.com repository in the ``gh-pages`` directory.)
  - Push the built site: ``cd gh-pages`` and ``git push origin master``.

- Post release notes on mailing lists, blog, Twitter, etc.

  - scikit-image@python.org
  - 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 master 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 = .*
