CI: revert macos-14 runners, migrate to tox v4-exclusive settings, add Python 3.13

.github/workflows/tox.yml

@@ -14,7 +14,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest] # All OSes pass except Windows because tests need Unix-only fcntl, grp, pwd, etc.
+        unsupported: [false]
+        os:
+         - ubuntu-latest
+         # not defaulting to macos-latest: Python <= 3.9 was missing from macos-14 @ arm64
+         - macos-13
+         # Not testing Windows, because tests need Unix-only fcntl, grp, pwd, etc.
         python-version:
          # CPython <= 3.7 is EoL since 2023-06-27
          - "3.7"
@@ -26,6 +31,19 @@ jobs:
          # PyPy <= 3.8 is EoL since 2023-06-16
          - "pypy-3.9"
          - "pypy-3.10"
+        include:
+         # Note: potentially "universal2" release
+         # https://github.com/actions/runner-images/issues/9741
+         - os: macos-latest
+           python-version: "3.12"
+           unsupported: false
+         # will run these without showing red CI results should they fail
+         - os: macos-latest
+           python-version: "3.13"
+           unsupported: true
+         - os: ubuntu-latest
+           python-version: "3.13"
+           unsupported: true
     steps:
       - uses: actions/checkout@v4
       - name: Using Python ${{ matrix.python-version }}
@@ -35,10 +53,14 @@ jobs:
           cache: pip
           cache-dependency-path: requirements_test.txt
           check-latest: true
+          allow-prereleases: ${{ matrix.unsupported }}
       - name: Install Dependencies
         run: |
           python -m pip install --upgrade pip
           python -m pip install tox
       - run: tox -e run-module
+        continue-on-error: ${{ matrix.unsupported }}
       - run: tox -e run-entrypoint
+        continue-on-error: ${{ matrix.unsupported }}
       - run: tox -e py
+        continue-on-error: ${{ matrix.unsupported }}

tox.ini

@@ -6,24 +6,27 @@ envlist =
   pycodestyle,
   run-entrypoint,
   run-module,
-skipsdist = false
-; Can't set skipsdist and use_develop in tox v4 to true due to https://github.com/tox-dev/tox/issues/2730
 
 [testenv]
-use_develop = true
+package = editable
 commands = pytest --cov=gunicorn {posargs}
 deps =
   -rrequirements_test.txt
 
 [testenv:run-entrypoint]
+package = wheel
+deps =
 # entry point: console script (provided by setuptools from pyproject.toml)
 commands = python -c 'import subprocess; cmd_out = subprocess.check_output(["gunicorn", "--version"])[:79].decode("utf-8", errors="replace"); print(cmd_out); assert cmd_out.startswith("gunicorn ")'
 
 [testenv:run-module]
+package = wheel
+deps =
 # runpy (provided by module.__main__)
 commands = python -c 'import sys,subprocess; cmd_out = subprocess.check_output([sys.executable, "-m", "gunicorn", "--version"])[:79].decode("utf-8", errors="replace"); print(cmd_out); assert cmd_out.startswith("gunicorn ")'
 
 [testenv:lint]
+no_package = true
 commands =
   pylint -j0 \
     --max-line-length=120 \
@@ -44,6 +47,7 @@ deps =
   pylint==2.17.4
 
 [testenv:docs-lint]
+no_package = true
 allowlist_externals =
   rst-lint
   bash
@@ -56,6 +60,7 @@ commands =
   bash -c "(set -o pipefail; rst-lint --encoding utf-8 docs/source/*.rst | grep -v 'Unknown interpreted text role\|Unknown directive type'); test $? == 1"
 
 [testenv:pycodestyle]
+no_package = true
 commands =
   pycodestyle gunicorn
 deps =