From fc9ff946b72c271d52c5ae08f3036905890de9b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <mgorny@gentoo.org>
Date: Tue, 21 Jan 2025 23:39:19 +0100
Subject: [PATCH] use cmake from PyPI only when system executable is not
 available (#7514)

Rather than pulling `cmake` from PyPI unconditionally, add it to build
dependencies only if the system `cmake` executable cannot be found.
This eliminates an unnecessary dependency on systems featuring CMake,
and ensures that whenever possible, a downstream patched CMake version
is used that is more compatible with the system in question.
---
 src/api/python/pyproject.toml | 2 +-
 src/api/python/setup.py       | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/api/python/pyproject.toml b/src/api/python/pyproject.toml
index ead5d1b2d..380744c87 100644
--- a/src/api/python/pyproject.toml
+++ b/src/api/python/pyproject.toml
@@ -1,3 +1,3 @@
 [build-system]
-requires = ["setuptools>=70", "cmake"]
+requires = ["setuptools>=70"]
 build-backend = "setuptools.build_meta"
diff --git a/src/api/python/setup.py b/src/api/python/setup.py
index 9590d78ce..8cd5afdaa 100644
--- a/src/api/python/setup.py
+++ b/src/api/python/setup.py
@@ -88,6 +88,11 @@ else:
     LIBRARY_FILE = "libz3.so"
     EXECUTABLE_FILE = "z3"
 
+# check if cmake is available, and pull it in via PyPI if necessary
+SETUP_REQUIRES = []
+if not shutil.which("cmake"):
+    SETUP_REQUIRES += ["cmake"]
+
 def rmtree(tree):
     if os.path.exists(tree):
         shutil.rmtree(tree, ignore_errors=False)
@@ -327,6 +332,7 @@ setup(
     license='MIT License',
     keywords=['z3', 'smt', 'sat', 'prover', 'theorem'],
     packages=['z3'],
+    setup_requires = SETUP_REQUIRES,
     install_requires = ["importlib-resources; python_version < '3.9'"],
     include_package_data=True,
     package_data={