Add support for Python 3.12.4

Release announcement:
https://blog.python.org/2024/06/python-3124-released.html

Changelog:
https://docs.python.org/3.12/whatsnew/changelog.html

Binary builds:
https://github.com/heroku/heroku-buildpack-python/actions/runs/9414066018

GUS-W-14846781.

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [Unreleased]
 
+- Added support for Python 3.12.4. ([#1591](https://github.com/heroku/heroku-buildpack-python/pull/1591))
+- Changed the default Python version for new apps from 3.12.3 to 3.12.4. ([#1591](https://github.com/heroku/heroku-buildpack-python/pull/1591))
 
 ## [v250] - 2024-04-26
 

README.md

@@ -42,7 +42,7 @@ A `requirements.txt` must be present at the root of your application's repositor
 
 To specify your python version, you also need a `runtime.txt` file - unless you are using the default Python runtime version.
 
-Current default Python Runtime: Python 3.12.3
+Current default Python Runtime: Python 3.12.4
 
 Alternatively, you can provide a `setup.py` file, or a `Pipfile`.
 Using `pipenv` will generate `runtime.txt` at build time if one of the field `python_version` or `python_full_version` is specified in the `requires` section of your `Pipfile`.
@@ -60,7 +60,7 @@ Specify a Python Runtime
 
 Supported runtime options include:
 
-- `python-3.12.3` on all [supported stacks](https://devcenter.heroku.com/articles/stack#stack-support-details)
+- `python-3.12.4` on all [supported stacks](https://devcenter.heroku.com/articles/stack#stack-support-details)
 - `python-3.11.9` on all [supported stacks](https://devcenter.heroku.com/articles/stack#stack-support-details)
 - `python-3.10.14` on all [supported stacks](https://devcenter.heroku.com/articles/stack#stack-support-details)
 - `python-3.9.19` on Heroku-20 and Heroku-22 only

bin/default_pythons

@@ -5,7 +5,7 @@
 # the env vars to subprocesses.
 # shellcheck disable=2034
 
-LATEST_312="python-3.12.3"
+LATEST_312="python-3.12.4"
 LATEST_311="python-3.11.9"
 LATEST_310="python-3.10.14"
 LATEST_39="python-3.9.19"

spec/fixtures/pipenv_and_runtime_txt/runtime.txt

@@ -1 +1 @@
-python-3.12.3
+python-3.12.4

spec/fixtures/python_3.12/runtime.txt

@@ -1 +1 @@
-python-3.12.3
+python-3.12.4

spec/fixtures/runtime_txt_only/runtime.txt

@@ -1 +1 @@
-python-3.12.3
+python-3.12.4

spec/fixtures/runtime_txt_with_stray_whitespace/runtime.txt

@@ -1,3 +1,3 @@
 
- python-3.12.3 
+ python-3.12.4 
 

spec/hatchet/python_version_spec.rb

@@ -54,15 +54,11 @@
       end
     end
 
-    # TODO: Enable on Heroku-24 after the default Python version next changes (for the 3.12.4
-    # release), since for now there isn't a historic buildpack version we can use in this test
-    # that is both compatible with the new Heroku-24 S3 asset URLs and also has a different
-    # default Python version so that we can test the sticky versions feature.
-    context 'with an app last built using an older default Python version', stacks: %w[heroku-20 heroku-22] do
+    context 'with an app last built using an older default Python version' do
       # This test performs an initial build using an older buildpack version, followed
       # by a build using the current version. This ensures that the current buildpack
       # can successfully read the version metadata written to the build cache in the past.
-      let(:buildpacks) { ['https://github.com/heroku/heroku-buildpack-python#v247'] }
+      let(:buildpacks) { ['https://github.com/heroku/heroku-buildpack-python#v250'] }
 
       it 'builds with the same Python version as the last build' do
         app.deploy do |app|
@@ -71,16 +67,16 @@
           app.push!
           expect(clean_output(app.output)).to include(<<~OUTPUT)
             remote: -----> Python app detected
-            remote: -----> No Python version was specified. Using the same version as the last build: python-3.12.2
+            remote: -----> No Python version was specified. Using the same version as the last build: python-3.12.3
             remote:        To use a different version, see: https://devcenter.heroku.com/articles/python-runtimes
             remote:  !     
             remote:  !     A Python security update is available! Upgrade as soon as possible to: python-#{LATEST_PYTHON_3_12}
             remote:  !     See: https://devcenter.heroku.com/articles/python-runtimes
             remote:  !     
             remote: -----> No change in requirements detected, installing from cache
-            remote: -----> Using cached install of python-3.12.2
+            remote: -----> Using cached install of python-3.12.3
           OUTPUT
-          expect(app.run('python -V')).to include('Python 3.12.2')
+          expect(app.run('python -V')).to include('Python 3.12.3')
         end
       end
     end
@@ -203,7 +199,7 @@
     include_examples 'builds with the requested Python version', LATEST_PYTHON_3_11
   end
 
-  context 'when runtime.txt contains python-3.12.3' do
+  context 'when runtime.txt contains python-3.12.4' do
     let(:app) { Hatchet::Runner.new('spec/fixtures/python_3.12') }
 
     include_examples 'builds with the requested Python version', LATEST_PYTHON_3_12

spec/hatchet/stack_spec.rb

@@ -9,7 +9,7 @@
     # can successfully read the stack metadata written to the build cache in the past.
     # The buildpack version chosen is one which had an older default Python version, so
     # we can also prove that clearing the cache didn't lose the Python version metadata.
-    let(:buildpacks) { ['https://github.com/heroku/heroku-buildpack-python#v247'] }
+    let(:buildpacks) { ['https://github.com/heroku/heroku-buildpack-python#v250'] }
     let(:app) { Hatchet::Runner.new('spec/fixtures/python_version_unspecified', buildpacks:) }
 
     it 'clears the cache before installing again whilst preserving the sticky Python version' do
@@ -22,15 +22,15 @@
         # TODO: The requirements output shouldn't say "installing from cache", since it's not.
         expect(clean_output(app.output)).to include(<<~OUTPUT)
           remote: -----> Python app detected
-          remote: -----> No Python version was specified. Using the same version as the last build: python-3.12.2
+          remote: -----> No Python version was specified. Using the same version as the last build: python-3.12.3
           remote:        To use a different version, see: https://devcenter.heroku.com/articles/python-runtimes
           remote:  !     
           remote:  !     A Python security update is available! Upgrade as soon as possible to: python-#{LATEST_PYTHON_3_12}
           remote:  !     See: https://devcenter.heroku.com/articles/python-runtimes
           remote:  !     
           remote: -----> Stack has changed from heroku-22 to heroku-24, clearing cache
           remote: -----> No change in requirements detected, installing from cache
-          remote: -----> Installing python-3.12.2
+          remote: -----> Installing python-3.12.3
           remote: -----> Installing pip #{PIP_VERSION}, setuptools #{SETUPTOOLS_VERSION} and wheel #{WHEEL_VERSION}
           remote: -----> Installing SQLite3
           remote: -----> Installing requirements with pip

spec/spec_helper.rb

@@ -10,7 +10,7 @@
 LATEST_PYTHON_3_9 = '3.9.19'
 LATEST_PYTHON_3_10 = '3.10.14'
 LATEST_PYTHON_3_11 = '3.11.9'
-LATEST_PYTHON_3_12 = '3.12.3'
+LATEST_PYTHON_3_12 = '3.12.4'
 DEFAULT_PYTHON_VERSION = LATEST_PYTHON_3_12
 
 # The requirement versions are effectively buildpack constants, however, we want