PyPy’s Release Process

Release Policy

We try to create a stable release a few times a year. These are released on a branch named like release-pypy3.5-v2.x or release-pypy3.5-v4.x, and each release is tagged, for instance release-pypy3.5-v4.0.1.

The release version number should be bumped. A micro release increment means there were no changes that justify rebuilding c-extension wheels, since the wheels are marked with only major.minor version numbers. It is ofen not clear what constitues a “major” release verses a “minor” release, the release manager can make that call.

After release, inevitably there are bug fixes. It is the responsibility of the commiter who fixes a bug to make sure this fix is on the release branch, so that we can then create a tagged bug-fix release, which will hopefully happen more often than stable releases.

How to Create a PyPy Release

As a meta rule setting up issues in the tracker for items here may help not forgetting things. A set of todo files may also work.

Check and prioritize all issues for the release, postpone some if necessary, create new issues also as necessary. An important thing is to get the documentation into an up-to-date state!

Release Steps

Make the release branch

This is needed only in case you are doing a new major version; if not, you can probably reuse the existing release branch.

We want to be able to freely merge default into the branch and vice-versa; thus we need to do a complicate dance to avoid to patch the version number when we do a merge:

$ hg up -r default
$ # edit the version to e.g. 7.0.0-final
$ hg ci
$ hg branch release-pypy2.7-v7.x && hg ci
$ hg up -r default
$ # edit the version to 7.1.0-alpha0
$ hg ci
$ hg up -r release-pypy2.7-v7.x
$ hg merge default
$ # edit the version to AGAIN 7.0.0-final
$ hg ci

Then, we need to do the same for the 3.x branch:

$ hg up -r py3.5
$ hg merge default # this brings the version fo 7.1.0-alpha0
$ hg branch release-pypy3.5-v7.x
$ # edit the version to 7.0.0-final
$ hg ci
$ hg up -r py3.5
$ hg merge release-pypy3.5-v7.x
$ # edit the version to 7.1.0-alpha0
$ hg ci

To change the version, you need to edit three files:

  • module/sys/ the PYPY_VERSION should be something like (7, 3, 10, "final", 0) or (7, 3, 9, "candidate", 2) for rc2.
  • module/cpyext/include/patchlevel.h: the PYPY_VERSION should be something like “7.3.10” for the final release or “7.3.10-candidate3” for rc3.
  • doc/

Add tags to the repo. Never change tags once commited: it breaks downstream packaging workflows.

  • Make sure the version checks pass (they ensure and patchlevel.h agree)
  • Make sure the tag matches the version in While the script checks this, it is too late to change once the tags are public

Other steps

  • Make sure the RPython builds on the buildbot pass with no failures

  • Maybe bump the SOABI number in module/imp/importing. This has many implications, so make sure the PyPy community agrees to the change. Wheels will use the major.minor release numbers in the name, so bump them if there is an incompatible change to cpyext.

  • Make sure the binary-testing CI is clean, or that the failures are understood.

  • Update and write documentation

    • update pypy/doc/contributor.rst (and possibly LICENSE) pypy/doc/tool/ generates the list of contributors
    • write release announcement pypy/doc/release-VERSION.rst The release announcement should contain a direct link to the download page
    • Add the new files to pypy/doc/index-of-release-notes.rst
  • Build and upload the release tar-balls

    • go to pypy/tool/release and run <release branch> The following JIT binaries should be built, however, we need more buildbots windows-64, linux-32, linux-64, macos_x86_64, macos_arm64, aarch64, s390x

    • wait for builds to complete, make sure there are no failures

    • send out a mailing list message asking for people to test before uploading to prevent having to upload more than once

    • add a tag on the pypy/jitviewer repo that corresponds to pypy release, so that the source tarball can be produced in the next steps

    • download the builds, repackage binaries. Tag the release-candidate version (it is important to mark this as a candidate since usually at least two tries are needed to complete the process) and download and repackage source from the buildbot. You may find it convenient to use the script in pypy/tool/release to do this.

      Also repackage and upload source “-src.tar.bz2”

    • Upload binaries to Add the files to the versions.json in pypy/tools/release, upload it, and run the file in that directory. This file is used by various downstream tools like “github actions” to find valid pypy downloads. It takes an hour for to sync. Note the “latest_pypy” attribute: it is per-python-version. So if the new release overrides a current latest_pypy (both are 2.7.18, for instance), you must find the older version and set its “lastest_pypy” to “false” or (and the various tools) will fail.

  • Send out a mailing list message asking for last-minute comments and testing


    • update with the checksum hashes produced from the script or by hand and the download pages
    • post announcement on
    • send announcements to, pypy-dev, python-list, python-announce, python-dev …
  • If all is OK, document the released version and suggest popular tools update to support it. Github actions will pick up the versions.json.