From 9d2d6adc3550de1a52428e5289a9a0136f1b24b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <mgorny@gentoo.org>
Date: Mon, 10 Feb 2025 20:06:51 +0100
Subject: [PATCH] Support using system CMake and Ninja

Add the dependencies on PyPI `cmake` and `ninja` packages only
if the respective tool cannot be found, in order to support using
system executables.  This avoids unnecessary dependencies on third-party
binary packages from PyPI, and improves portability be enabling use
of downstream patching.
---
 pyproject.toml | 2 --
 setup.py       | 7 +++++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index ed97244c2..4d3bb6749 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,5 @@
 [build-system]
 requires = [
     "setuptools",
-    "cmake>=3.12",
-    "ninja>=1.10"
 ]
 build-backend = "setuptools.build_meta"
diff --git a/setup.py b/setup.py
index adfd89af7..3eb0d25a4 100644
--- a/setup.py
+++ b/setup.py
@@ -135,6 +135,12 @@ def build_extension(self, ext):
 with open("README.md", "r", encoding="utf-8") as fh:
     long_description = fh.read()
 
+setup_requires = []
+if which("cmake") is None:
+    setup_requires += ["cmake>=3.12"]
+if which("ninja") is None:
+    setup_requires += ["ninja>=1.10"]
+
 setup(
     name="PyMatching",
     version=version['__version__'],
@@ -153,6 +159,7 @@ def build_extension(self, ext):
         'console_scripts': ['pymatching=pymatching._cli_argv:cli_argv'],
     },
     python_requires=">=3.7",
+    setup_requires=setup_requires,
     install_requires=['scipy', 'numpy==1.*', 'networkx', 'matplotlib'],
     # Needed on Windows to avoid the default `build` colliding with Bazel's `BUILD`.
     options={'build': {'build_base': 'python_build_stim'}},