fix: try supporting older CMake

Co-authored-by: Jean-Christophe Fillion-Robin <[email protected]>

Author: henryiii

.github/workflows/ci.yml

@@ -51,6 +51,9 @@ jobs:
           - python-version: "3.9"
             runs-on: ubuntu-latest
             cmake: "3.20.x"
+          - python-version: "3.10"
+            runs-on: ubuntu-latest
+            cmake: "3.15.x"
 
     steps:
       - uses: actions/checkout@v4
@@ -67,6 +70,9 @@ jobs:
         with:
           cmake-version: ${{ matrix.cmake }}
 
+      - run: pipx install ninja
+        if: matrix.cmake == '3.15.x'
+
       - uses: yezz123/setup-uv@v4
 
       - name: Install package

src/cython_cmake/cmake/UseCython.cmake

@@ -64,6 +64,9 @@
 # limitations under the License.
 #=============================================================================
 
+if(CMAKE_VERSION VERSION_LESS "3.7")
+  message(SEND_ERROR "CMake 3.7 required for DEPFILE")
+endif()
 
 function(Cython_compile_pyx)
   set(_options )
@@ -116,7 +119,11 @@ function(Cython_compile_pyx)
   set(generated_files)
 
   foreach(_source_file IN LISTS _source_files)
-    cmake_path(GET _source_file STEM _name)
+
+    # Can use cmake_path for CMake 3.20+
+    # cmake_path(GET _source_file STEM _name)
+    get_filename_component(_name "${_source_file}" NAME_WE)
+
     set(generated_file "${CMAKE_CURRENT_BINARY_DIR}/${_name}.${_language_extension}")
     set_source_files_properties(${generated_file} PROPERTIES GENERATED TRUE)