Add support for Python 3.11 (#1379)

https://blog.python.org/2022/10/python-3110-is-now-available.html
https://www.python.org/downloads/release/python-3110/

GUS-W-10333186.

Author: edmorley

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Add support for Python 3.11 ([#1379](https://github.com/heroku/heroku-buildpack-python/pull/1379)).
 
 ## v221 (2022-10-12)
 

README.md

@@ -60,6 +60,7 @@ Specify a Python Runtime
 
 Supported runtime options include:
 
+- `python-3.11.0` on all [supported stacks](https://devcenter.heroku.com/articles/stack#stack-support-details)
 - `python-3.10.8` on all [supported stacks](https://devcenter.heroku.com/articles/stack#stack-support-details)
 - `python-3.9.15` on all [supported stacks](https://devcenter.heroku.com/articles/stack#stack-support-details)
 - `python-3.8.15` on Heroku-18 and Heroku-20 only

bin/default_pythons

@@ -5,6 +5,7 @@
 # the env vars to subprocesses.
 # shellcheck disable=2034
 
+LATEST_311="python-3.11.0"
 LATEST_310="python-3.10.8"
 LATEST_39="python-3.9.15"
 LATEST_38="python-3.8.15"

bin/steps/pipenv-python-version

@@ -46,6 +46,9 @@ if [[ -f $BUILD_DIR/Pipfile ]]; then
                     3.10)
                         echo "${LATEST_310}" > "${BUILD_DIR}/runtime.txt"
                         ;;
+                    3.11)
+                        echo "${LATEST_311}" > "${BUILD_DIR}/runtime.txt"
+                        ;;
                 esac
             fi
 

bin/steps/python

@@ -45,6 +45,9 @@ function warn_if_patch_update_available() {
 }
 
 case "${PYTHON_VERSION}" in
+  python-3.11.*)
+    warn_if_patch_update_available "${PYTHON_VERSION}" "${LATEST_311}"
+    ;;
   python-3.10.*)
     warn_if_patch_update_available "${PYTHON_VERSION}" "${LATEST_310}"
     ;;

builds/runtimes/python

@@ -20,7 +20,7 @@ fi
 
 # See: https://www.python.org/downloads/ -> "OpenPGP Public Keys"
 case "${VERSION}" in
-  3.10.*)
+  3.1[0-1].*)
     # https://keybase.io/pablogsal/
     GPG_KEY_FINGERPRINT='A035C8C19219BA821ECEA86B64E628F8D684696D'
     ;;
@@ -85,7 +85,7 @@ if [[ "${VERSION}" != 3.7.* ]]; then
   )
 fi
 
-if [[ "${VERSION}" == 3.10.* ]]; then
+if [[ "${VERSION}" != 3.[7-9].* ]]; then
   CONFIGURE_OPTS+=(
     # Shared builds are beneficial for a number of reasons:
     # - Reduces the size of the build, since it avoids the duplication between
@@ -108,6 +108,17 @@ if [[ "${VERSION}" == 3.10.* ]]; then
   )
 fi
 
+if [[ "${VERSION}" == 3.11.* ]]; then
+  CONFIGURE_OPTS+=(
+    # Skip building the test modules, since we remove them after the build anyway.
+    # This feature was added in Python 3.10+, however it wasn't until Python 3.11
+    # that compatibility issues between it and PGO were fixed:
+    # https://github.com/python/cpython/pull/29315
+    # TODO: See if a backport of that fix would be accepted to Python 3.10.
+    "--disable-test-modules"
+  )
+fi
+
 ./configure "${CONFIGURE_OPTS[@]}"
 
 # Using LDFLAGS we instruct the linker to omit all symbol information from the final binary
@@ -134,8 +145,8 @@ fi
 
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
-# TODO: Explore using --disable-test-modules once the PGO fix is in a released Python version:
-# https://bugs.python.org/issue45668
+# This is a no-op on Python 3.11+, since --disable-test-modules will have prevented
+# the test files from having been built in the first place.
 find "${OUT_PREFIX}" -depth -type d -a \( -name 'test' -o -name 'tests' -o -name 'idle_test' \) -print -exec rm -rf '{}' +
 
 # The `make install` step automatically generates `.pyc` files for the stdlib, however:

builds/runtimes/python-3.11.0

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python
+
+# shellcheck source-path=SCRIPTDIR
+source "$(dirname "${0}")/python"

spec/fixtures/pipenv_python_3.11/Pipfile

@@ -0,0 +1,12 @@
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+urllib3 = "*"
+
+[dev-packages]
+
+[requires]
+python_version = "3.11"

spec/fixtures/pipenv_python_3.11/Pipfile.lock

@@ -0,0 +1 @@
+urllib3