Update to Python 3.10 as minimum (3.9 is EOL)

.github/workflows/test.yml

@@ -20,13 +20,14 @@ jobs:
   test_spin:
     strategy:
       matrix:
-        python_version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14-dev"]
+        python_version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
         os: [ubuntu-latest, windows-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v5
       - uses: actions/setup-python@v6
         with:
+          id: setup-python
           python-version: ${{ matrix.python_version }}
           allow-prereleases: true
           cache: "pip"
@@ -37,4 +38,4 @@ jobs:
           sudo apt-get install -y gdb lcov
       - name: Tests PyTest
         run: |
-          pipx run nox --forcecolor -s test
+          pipx run --python '${{ steps.setup-python.outputs.python-path }}' nox --forcecolor -s test

README.md

@@ -296,6 +296,9 @@ nox -s test -- -v
 nox -s test -- -v spin/tests/test_meson.py
 ```
 
+`spin` takes a slightly more conservative approach than [SPEC 0](https://scientific-python.org/specs/spec-0000/), and
+supports all non-EOL versions of Python.
+
 ## History
 
 The `dev.py` tool was [proposed for SciPy](https://github.com/scipy/scipy/issues/15489) by Ralf Gommers and [implemented](https://github.com/scipy/scipy/pull/15959) by Sayantika Banik, Eduardo Naufel Schettino, and Ralf Gommers (also see [Sayantika's blog post](https://labs.quansight.org/blog/the-evolution-of-the-scipy-developer-cli)).

example_pkg_src/pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "example_pkg"
 version = "0.0dev0"
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 description = "spin Example Package"
 
 [build-system]

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "spin"
-requires-python = ">=3.9"
+requires-python = ">=3.10"  # Oldest non-EOL Python here
 description = "Developer tool for scientific Python libraries"
 readme = "README.md"
 license = {file = "LICENSE"}
@@ -15,7 +15,6 @@ classifiers = [
   "License :: OSI Approved :: BSD License",
   "Operating System :: OS Independent",
   "Programming Language :: Python :: 3",
-  "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",

spin/__main__.py

@@ -6,7 +6,6 @@
 import sys
 import textwrap
 import traceback
-from typing import Union
 
 import click
 
@@ -31,7 +30,7 @@
 )
 
 
-def _detect_config_dir(path: pathlib.Path) -> Union[pathlib.Path, None]:
+def _detect_config_dir(path: pathlib.Path) -> pathlib.Path | None:
     path = path.resolve()
     files = os.listdir(path)
     if any(f in files for f in config_filenames):

spin/cmds/meson.py

@@ -8,7 +8,6 @@
 import sys
 from enum import Enum
 from pathlib import Path
-from typing import Union
 
 import click
 
@@ -36,7 +35,7 @@ def _meson_cli():
         return [meson_cli]
 
 
-def editable_install_path(distname: str) -> Union[str, None]:
+def editable_install_path(distname: str) -> str | None:
     """Return path of the editable install for package `distname`.
 
     If the package is not an editable install, return None.
@@ -191,15 +190,15 @@ def _get_site_packages(build_dir: str) -> str:
     return site_packages
 
 
-def _meson_version() -> Union[str, None]:
+def _meson_version() -> str | None:
     try:
         p = _run(_meson_cli() + ["--version"], output=False, echo=False)
         return p.stdout.decode("ascii").strip()
     except:
         return None
 
 
-def _meson_version_configured(build_dir: str) -> Union[str, None]:
+def _meson_version_configured(build_dir: str) -> str | None:
     try:
         meson_info_fn = os.path.join(build_dir, "meson-info", "meson-info.json")
         with open(meson_info_fn) as f: