cleanup: drop Python 3.11 support

Make Python 3.12 the minimum supported version. Python 3.11 is in
security-fix only mode upstream, and downstream (RHEL) has stopped
using it. This reduces the CI test matrix and enables use of Python
3.12 features.

- Remove Python 3.11 classifier from pyproject.toml and e2e plugins
- Bump requires-python from >=3.11 to >=3.12
- Bump ruff target-version from py311 to py312
- Remove 3.11 from CI test matrix (unit + e2e workflows)
- Update check, publish, and docs workflows to use Python 3.12
- Remove all 3.11 check-success entries from Mergify config
- Update example Containerfile to default to Python 3.12

Closes: #948
Made-with: Cursor

Author: smoparth

.github/workflows/check.yaml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.11"  # minimum supported lang version
+          python-version: "3.12"  # minimum supported lang version
 
       - name: Install dependencies
         run: python -m pip install hatch 'click!=8.3.0'
@@ -39,7 +39,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.11"  # minimum supported lang version
+          python-version: "3.12"  # minimum supported lang version
 
       - name: Install dependencies
         run: python -m pip install hatch 'click!=8.3.0'
@@ -60,7 +60,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.11"  # minimum supported lang version
+          python-version: "3.12"  # minimum supported lang version
 
       - name: Install dependencies
         run: python -m pip install hatch 'click!=8.3.0'
@@ -81,7 +81,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.11"  # minimum supported lang version
+          python-version: "3.12"  # minimum supported lang version
 
       - name: Install dependencies
         run: python -m pip install hatch 'click!=8.3.0'
@@ -118,7 +118,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.11"  # minimum supported lang version
+          python-version: "3.12"  # minimum supported lang version
 
       - name: Install dependencies
         run: python -m pip install hatch 'click!=8.3.0'

.github/workflows/python-publish.yaml

@@ -25,7 +25,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v6
       with:
-        python-version: '3.11'
+        python-version: '3.12'
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip

.github/workflows/test.yaml

@@ -13,7 +13,6 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "3.11"
           - "3.12"
           - "3.13"
           - "3.14"
@@ -71,7 +70,6 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "3.11"
           - "3.12"
           - "3.13"
           - "3.14"
@@ -91,8 +89,6 @@ jobs:
         exclude:
           # macOS tests are slower and congested
           # only run macOS tests on latest stable Python version
-          - os: macos-latest
-            python-version: "3.11"
           - os: macos-latest
             python-version: "3.12"
           - os: macos-latest

.mergify.yml

@@ -29,8 +29,6 @@ pull_request_rules:
           - "-draft"
 
           # Unit tests
-          - check-success=unit (3.11, 1.75, ubuntu-latest)
-          - check-success=unit (3.11, 1.75, macos-latest)
           - check-success=unit (3.12, 1.75, ubuntu-latest)
           - check-success=unit (3.12, 1.75, macos-latest)
           - check-success=unit (3.13, 1.75, ubuntu-latest)
@@ -42,13 +40,6 @@ pull_request_rules:
           - check-success=mypy
 
           # E2E test suites (consolidated from individual tests)
-          # Python 3.11 - Ubuntu only (macOS excluded)
-          - check-success=e2e (3.11, 1.75, ci_bootstrap_parallel_suite, ubuntu-latest)
-          - check-success=e2e (3.11, 1.75, ci_bootstrap_suite, ubuntu-latest)
-          - check-success=e2e (3.11, 1.75, ci_build_suite, ubuntu-latest)
-          - check-success=e2e (3.11, 1.75, ci_config_suite, ubuntu-latest)
-          - check-success=e2e (3.11, 1.75, ci_specialized_suite, ubuntu-latest)
-          - check-success=e2e (3.11, 1.75, ci_workflow_suite, ubuntu-latest)
           # Python 3.12 - Ubuntu only (macOS excluded)
           - check-success=e2e (3.12, 1.75, ci_bootstrap_parallel_suite, ubuntu-latest)
           - check-success=e2e (3.12, 1.75, ci_bootstrap_suite, ubuntu-latest)

.readthedocs.yaml

@@ -3,7 +3,7 @@ version: 2
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.11"
+    python: "3.12"
 
 sphinx:
   configuration: docs/conf.py

docs/example/Containerfile

@@ -18,7 +18,7 @@ ENV APP_ROOT=/opt/app-root \
     PATH=/opt/app-root/src/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
 
 # Python, pip, and virtual env settings
-ARG PYTHON_VERSION=3.11
+ARG PYTHON_VERSION=3.12
 ENV PYTHON_VERSION=${PYTHON_VERSION} \
     PYTHON=python${PYTHON_VERSION} \
     PIP_NO_CACHE_DIR=off \

e2e/flit_core_override/pyproject.toml

@@ -16,13 +16,12 @@ classifiers = [
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3 :: Only",
-    "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: Implementation :: CPython",
     "Topic :: Utilities",
 ]
 
-requires-python = ">=3.11"
+requires-python = ">=3.12"
 
 dependencies = []
 

e2e/fromager_hooks/pyproject.toml

@@ -16,13 +16,12 @@ classifiers = [
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3 :: Only",
-    "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: Implementation :: CPython",
     "Topic :: Utilities",
 ]
 
-requires-python = ">=3.11"
+requires-python = ">=3.12"
 
 dependencies = []
 

e2e/stevedore_override/pyproject.toml

@@ -16,13 +16,12 @@ classifiers = [
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3 :: Only",
-    "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: Implementation :: CPython",
     "Topic :: Utilities",
 ]
 
-requires-python = ">=3.11"
+requires-python = ">=3.12"
 
 dependencies = []
 

pyproject.toml

@@ -21,15 +21,14 @@ classifiers = [
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3 :: Only",
-    "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: 3.14",
     "Programming Language :: Python :: Implementation :: CPython",
     "Topic :: Utilities",
 ]
 
-requires-python = ">=3.11"
+requires-python = ">=3.12"
 
 dependencies = [
     "click>=8.1.7",
@@ -154,7 +153,7 @@ source = "vcs"
 packages = ["src/fromager"]
 
 [tool.ruff]
-target-version = "py311"
+target-version = "py312"
 # same as black's default line length
 line-length = 88
 exclude = [