ci: print out packages, test on CMake 3.20

Signed-off-by: Henry Schreiner <[email protected]>

Author: henryiii

.github/workflows/ci.yml

@@ -34,7 +34,9 @@ jobs:
           pipx run nox -s pylint
 
   checks:
-    name: Check Python ${{ matrix.python-version }} on ${{ matrix.runs-on }}
+    name:
+      🐍 ${{ matrix.python-version }} on ${{ matrix.runs-on }} ${{ matrix.cmake
+      }}
     runs-on: ${{ matrix.runs-on }}
     needs: [pre-commit]
     strategy:
@@ -46,6 +48,9 @@ jobs:
         include:
           - python-version: pypy-3.10
             runs-on: ubuntu-latest
+          - python-version: "3.9"
+            runs-on: ubuntu-latest
+            cmake: "3.20.x"
 
     steps:
       - uses: actions/checkout@v4
@@ -57,6 +62,11 @@ jobs:
           python-version: ${{ matrix.python-version }}
           allow-prereleases: true
 
+      - uses: jwlawson/actions-setup-cmake@v2
+        if: matrix.cmake != ''
+        with:
+          cmake-version: ${{ matrix.cmake }}
+
       - uses: yezz123/setup-uv@v4
 
       - name: Install package

tests/conftest.py

@@ -0,0 +1,38 @@
+from __future__ import annotations
+
+import importlib.metadata
+import shutil
+import subprocess
+
+
+def _get_program(name: str) -> str:
+    res = shutil.which(name)
+    if res is None:
+        return f"No {name} executable found on PATH"
+    result = subprocess.run(
+        [res, "--version"], check=True, text=True, capture_output=True
+    )
+    version = result.stdout.splitlines()[0]
+    return f"{res}: {version}"
+
+
+def pytest_report_header() -> str:
+    interesting_packages = {
+        "cmake",
+        "ninja",
+        "packaging",
+        "pip",
+        "scikit-build-core",
+    }
+    valid = []
+    for package in interesting_packages:
+        try:
+            version = importlib.metadata.version(package)
+        except ModuleNotFoundError:
+            continue
+        valid.append(f"{package}=={version}")
+    reqs = " ".join(sorted(valid))
+    pkg_line = f"installed packages of interest: {reqs}"
+    prog_lines = [_get_program(n) for n in ("cmake3", "cmake", "ninja")]
+
+    return "\n".join([pkg_line, *prog_lines])

tests/packages/simple/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.20...3.26)
+cmake_minimum_required(VERSION 3.20...3.29)
 project(${SKBUILD_PROJECT_NAME} LANGUAGES C)
 
 find_package(