fix: ninja wasn't being used if present (#310)

Also adds a way to test downstream packages manually.

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

docs/examples/getting_started/fortran/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.15...3.26)
+cmake_minimum_required(VERSION 3.17.2...3.26)
 project(${SKBUILD_PROJECT_NAME} LANGUAGES C Fortran)
 
 find_package(

docs/examples/getting_started/fortran/pyproject.toml

@@ -6,3 +6,7 @@ build-backend = "scikit_build_core.build"
 name = "example"
 version = "0.0.1"
 dependencies = ["numpy"]
+
+[tool.scikit-build]
+ninja.minimum-version = "1.10"
+cmake.minimum-version = "3.17.2"

noxfile.py

@@ -114,3 +114,75 @@ def test_doc_examples(session: nox.Session, example: str) -> None:
     session.chdir(f"docs/examples/getting_started/{example}")
     session.install(".", "--config-settings=cmake.verbose=true")
     session.run("python", "../test.py")
+
+
+@nox.session(reuse_venv=True)
+def downstream(session: nox.Session) -> None:
+    """
+    Build a downstream project.
+    """
+
+    # If running in manylinux:
+    #   docker run --rm -v $PWD:/sk -w /sk -t quay.io/pypa/manylinux2014_x86_64:latest \
+    #       pipx run --system-site-packages nox -s downstream -- https://github.com/...
+    # (requires tomli, so allowing access to system-site-packages)
+
+    if sys.version_info < (3, 11):
+        import tomli as tomllib
+    else:
+        import tomllib
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument("project", help="A project to build")
+    parser.add_argument("--subdir", help="A subdirectory to build")
+    args, remaining = parser.parse_known_args(session.posargs)
+
+    tmp_dir = Path(session.create_tmp())
+    proj_dir = tmp_dir / "_".join(args.project.split("/"))
+
+    session.install("build", "hatch-vcs", "hatchling")
+    session.install(".[pyproject]", "--no-build-isolation")
+
+    if proj_dir.is_dir():
+        session.chdir(proj_dir)
+        session.run("git", "pull", external=True)
+    else:
+        session.run(
+            "git",
+            "clone",
+            args.project,
+            *remaining,
+            proj_dir,
+            "--recurse-submodules",
+            external=True,
+        )
+        session.chdir(proj_dir)
+
+    # Read and strip requirements
+    pyproject_toml = Path("pyproject.toml")
+    with pyproject_toml.open("rb") as f:
+        pyproject = tomllib.load(f)
+    requires = [
+        x
+        for x in pyproject["build-system"]["requires"]
+        if "scikit-build-core" not in x.replace("_", "-")
+    ]
+    if not shutil.which("ninja"):
+        requires.append("ninja")
+    if not shutil.which("cmake"):
+        requires.append("cmake")
+    if requires:
+        session.install(*requires)
+
+    if args.subdir:
+        session.chdir(args.subdir)
+
+    session.run(
+        "python",
+        "-m",
+        "build",
+        "--no-isolation",
+        "--skip-dependency-check",
+        "--wheel",
+        ".",
+    )

pyproject.toml

@@ -237,7 +237,7 @@ exclude = []
 
 [tool.ruff.per-file-ignores]
 "tests/**" = ["T20"]
-"noxfile.py" = ["T20"]
+"noxfile.py" = ["T20", "TID251"]
 "src/scikit_build_core/resources/*.py" = ["PTH", "ARG002"]
 "src/scikit_build_core/_compat/**.py" = ["TID251"]
 "tests/conftest.py" = ["TID251"]

src/scikit_build_core/build/wheel.py

@@ -182,7 +182,9 @@ def _build_wheel_impl(
 
         generator = builder.config.env.get(
             "CMAKE_GENERATOR",
-            "MSVC" if sysconfig.get_platform().startswith("win") else "Unknown",
+            "MSVC"
+            if sysconfig.get_platform().startswith("win")
+            else "Default generator",
         )
         rich_print(
             f"[green]***[/green] [bold]Building project with [blue]{generator}[/blue]..."

src/scikit_build_core/builder/generator.py

@@ -80,7 +80,11 @@ def set_environment_for_gen(
         "win"
     ):
         # Non-MSVC Windows platforms require Ninja
-        env.setdefault("CMAKE_GENERATOR", "Ninja")
+        default = "Ninja"
+
+    # Try Ninja if it is available, even if make is CMake default
+    if default == "Unix Makefiles":
+        default = "Ninja"
 
     if env.get("CMAKE_GENERATOR", default or "Ninja") == "Ninja":
         min_ninja = Version(ninja_settings.minimum_version)

tests/packages/fortran_example/CMakeLists.txt

@@ -1,5 +1,5 @@
 # setup project ###
-cmake_minimum_required(VERSION 3.15...3.24)
+cmake_minimum_required(VERSION 3.17.2...3.24)
 
 project(
   fibby

tests/test_fortran.py

@@ -5,15 +5,25 @@
 from pathlib import Path
 
 import pytest
+from packaging.version import Version
 
 from scikit_build_core.build import build_wheel
+from scikit_build_core.program_search import (
+    best_program,
+    get_cmake_programs,
+    get_ninja_programs,
+)
 
 np = pytest.importorskip("numpy")
 
 DIR = Path(__file__).parent.resolve()
 FORTRAN_EXAMPLE = DIR / "packages/fortran_example"
 
 
+cmake_info = best_program(get_cmake_programs(), minimum_version=Version("3.17.2"))
+ninja_info = best_program(get_ninja_programs(), minimum_version=Version("1.10"))
+
+
 @pytest.mark.compile()
 @pytest.mark.configure()
 @pytest.mark.fortran()
@@ -22,6 +32,12 @@
     sysconfig.get_platform().startswith("win"),
     reason="No reasonable Fortran compiler for MSVC",
 )
+@pytest.mark.skipif(
+    cmake_info is None, reason="CMake needs to be 3.17.2+ to support Fortran with Ninja"
+)
+@pytest.mark.skipif(
+    ninja_info is None, reason="Ninja needs to be 1.10+ to support Fortran with CMake"
+)
 def test_pep517_wheel(tmp_path, monkeypatch, virtualenv):
     dist = tmp_path / "dist"
     dist.mkdir()