Add an option to avoid passing the python hints

Signed-off-by: Cristian Le <git@lecris.dev>

Author: LecrisUT

README.md

@@ -175,6 +175,9 @@ cmake.source-dir = "."
 # The CMAKE_TOOLCHAIN_FILE used for cross-compilation.
 cmake.toolchain-file = ""
 
+# Do not pass the current environment's python hints such as ``Python_EXECUTABLE``.
+cmake.python-hints = true
+
 # The versions of Ninja to allow.
 ninja.version = ">=1.5"
 

docs/reference/configs.md

@@ -198,6 +198,16 @@ print(mk_skbuild_docs())
   DEPRECATED in 0.8; use version instead.
 ```
 
+```{eval-rst}
+.. confval:: cmake.python-hints
+  :type: ``bool``
+  :default: true
+
+  Do not pass the current environment's python hints such as ``Python_EXECUTABLE``.
+  Primarily used for cross-compilation where the CMAKE_TOOLCHAIN_FILE should handle it
+  instead.
+```
+
 ```{eval-rst}
 .. confval:: cmake.source-dir
   :type: ``Path``

src/scikit_build_core/builder/builder.py

@@ -245,25 +245,26 @@ def configure(
         if self.settings.cmake.toolchain_file:
             cache_config["CMAKE_TOOLCHAIN_FILE"] = self.settings.cmake.toolchain_file
 
-        # Classic Find Python
-        cache_config["PYTHON_EXECUTABLE"] = Path(sys.executable)
-        cache_config["PYTHON_INCLUDE_DIR"] = python_include_dir
-        if python_library:
-            cache_config["PYTHON_LIBRARY"] = python_library
-
-        # Modern Find Python
-        for prefix in ("Python", "Python3"):
-            cache_config[f"{prefix}_EXECUTABLE"] = Path(sys.executable)
-            cache_config[f"{prefix}_ROOT_DIR"] = Path(sys.base_exec_prefix)
-            cache_config[f"{prefix}_INCLUDE_DIR"] = python_include_dir
-            cache_config[f"{prefix}_FIND_REGISTRY"] = "NEVER"
-            # FindPython may break if this is set - only useful on Windows
-            if python_library and sysconfig.get_platform().startswith("win"):
-                cache_config[f"{prefix}_LIBRARY"] = python_library
-            if python_sabi_library and sysconfig.get_platform().startswith("win"):
-                cache_config[f"{prefix}_SABI_LIBRARY"] = python_sabi_library
-            if numpy_include_dir:
-                cache_config[f"{prefix}_NumPy_INCLUDE_DIR"] = numpy_include_dir
+        if self.settings.cmake.python_hints:
+            # Classic Find Python
+            cache_config["PYTHON_EXECUTABLE"] = Path(sys.executable)
+            cache_config["PYTHON_INCLUDE_DIR"] = python_include_dir
+            if python_library:
+                cache_config["PYTHON_LIBRARY"] = python_library
+
+            # Modern Find Python
+            for prefix in ("Python", "Python3"):
+                cache_config[f"{prefix}_EXECUTABLE"] = Path(sys.executable)
+                cache_config[f"{prefix}_ROOT_DIR"] = Path(sys.base_exec_prefix)
+                cache_config[f"{prefix}_INCLUDE_DIR"] = python_include_dir
+                cache_config[f"{prefix}_FIND_REGISTRY"] = "NEVER"
+                # FindPython may break if this is set - only useful on Windows
+                if python_library and sysconfig.get_platform().startswith("win"):
+                    cache_config[f"{prefix}_LIBRARY"] = python_library
+                if python_sabi_library and sysconfig.get_platform().startswith("win"):
+                    cache_config[f"{prefix}_SABI_LIBRARY"] = python_sabi_library
+                if numpy_include_dir:
+                    cache_config[f"{prefix}_NumPy_INCLUDE_DIR"] = numpy_include_dir
 
         cache_config["SKBUILD_SOABI"] = get_soabi(self.config.env, abi3=limited_api)
 

src/scikit_build_core/resources/scikit-build.schema.json

@@ -106,6 +106,11 @@
         "toolchain-file": {
           "type": "string",
           "description": "The CMAKE_TOOLCHAIN_FILE used for cross-compilation."
+        },
+        "python-hints": {
+          "type": "boolean",
+          "default": true,
+          "description": "Do not pass the current environment's python hints such as ``Python_EXECUTABLE``."
         }
       }
     },

src/scikit_build_core/settings/skbuild_model.py

@@ -142,6 +142,13 @@ class CMakeSettings:
     The CMAKE_TOOLCHAIN_FILE used for cross-compilation.
     """
 
+    python_hints: bool = True
+    """
+    Do not pass the current environment's python hints such as ``Python_EXECUTABLE``.
+    Primarily used for cross-compilation where the CMAKE_TOOLCHAIN_FILE should handle it
+    instead.
+    """
+
 
 @dataclasses.dataclass
 class SearchSettings: