looks good

CMakeLists.txt

@@ -9,7 +9,7 @@ add_library(${TARGET_NAME} SHARED
 
 if (MSVC)
     target_compile_options(${TARGET_NAME} PRIVATE "/MP")
-    set_target_properties(${TARGET_NAME} PROPERTIES SUFFIX ".pyd")
+    set_target_properties(${TARGET_NAME} PROPERTIES SUFFIX ${SHARED_SUFFIX})
 elseif (APPLE)
     set_target_properties(${TARGET_NAME} PROPERTIES SUFFIX ${SHARED_SUFFIX})
     target_compile_options(${TARGET_NAME} PRIVATE ${ALL_COMP_ARGS})

contrib/champ/champ_module.c

@@ -1053,7 +1053,7 @@ static PyMethodDef champ_methods[] = {
   {NULL,		                    NULL}     /* sentinel */        
 };
 
-PyObject * PyInit__champ(void)
+PyMODINIT_FUNC PyInit__champ(void)
 {
   static struct PyModuleDef moduledef = {
     PyModuleDef_HEAD_INIT,

setup.py

@@ -196,6 +196,7 @@ def concat_paths(paths):
         lib_mode = "RUNTIME" if WIN else "LIBRARY"
 
         shared_suffix = sysconfig.get_config_var('EXT_SUFFIX')
+        print(f"shared_suffix: {shared_suffix}")
 
         cmake_args = [
             f"-DTARGET_NAME={target_name}",
@@ -264,23 +265,37 @@ def install_lib_to(self, sub_dir_list: list[str], lib_name: str) -> None:
         :lib_name: The filename of the library (without the extension).
         """
         lib_path = pathlib.Path(self.build_lib, *sub_dir_list)
+        suffix = sysconfig.get_config_var('EXT_SUFFIX')
         if WIN:
-            lib_path = lib_path / "Release" / f"{lib_name}.pyd"
+            lib_path = lib_path / "Release" / f"{lib_name}{suffix}"
         else:
-            lib_path = lib_path / f"{lib_name}.so"
-        dst = pathlib.Path(self.install_platlib, *sub_dir_list)
-        self.copy(str(lib_path), str(dst))
+            lib_path = lib_path / f"{lib_name}{suffix}"
+        dst = pathlib.Path(self.install_platlib, *sub_dir_list, f"{lib_name}{suffix}")
+        self.copy(str(lib_path), dst)
 
-    def install_pymol_lib(self) -> None:
+    def delete_conflicting_cmake_dir(self, sub_dir_list: list[str], lib_name: str) -> None:
         """
-        Installs PyMOL _cmd library
+        Deletes the conflicting directory if it exists.
+        :sub_dir_list: The subdirectories where the library is located
+            relative to the build_lib and install_platlib directories.
+        :lib_name: The filename of the library (without the extension).
         """
-        self.install_lib_to(["pymol"], "_cmd")
-
+        cmake_folder = pathlib.Path(self.build_lib, *sub_dir_list, f"{lib_name}{sysconfig.get_config_var('EXT_SUFFIX')}")
+        print(cmake_folder)
+        print(f"DELETE {cmake_folder}")
+        print(cmake_folder.exists())
+        if cmake_folder.exists() and cmake_folder.is_dir():
+            shutil.rmtree(cmake_folder)
+        print(cmake_folder.exists())
+        # if lib_name == "_champ":
+        #     exit(1)
     def run(self):
-        install.run(self)
+        self.delete_conflicting_cmake_dir(["pymol"], "_cmd")
+        self.delete_conflicting_cmake_dir(["chempy", "champ"], "_champ")
+        super().run()
         self.install_pymol_path()
-        self.install_pymol_lib()
+        self.install_lib_to(["pymol"], "_cmd")
+        self.install_lib_to(["chempy", "champ"], "_champ")
 
         if not self.no_launcher:
             self.make_launch_script()