PyPy Python implementation is no longer supported

Change effective on 26 September 2022

PyPy is an alternative implementation of Python.

The Heroku Python buildpack’s experimental support for PyPy runtimes has now been removed due to extremely low usage. As such, builds of apps using PyPy will now fail with a not-supported message.

Affected apps should either:

  1. Switch to the more commonly used CPython runtimes by updating runtime.txt to specify a supported Python version (in the form python-X.Y.Z) instead of pypy*.
  2. Switch to the container stack and use the upstream official PyPy Docker image instead.