try making ascii-only symbolic links to resolve UTF issues on Windows

.github/workflows/cmake.yml

@@ -284,8 +284,6 @@ jobs:
           -DLIBINT2_PYTHON=ON \
           -DCMAKE_PREFIX_PATH="${CONDA_PREFIX}" \
           ${{ matrix.cfg.libargs }}
-        cat build/build.ninja
-        ninja -t wincodepage
         cmake --build build --target install libint2-python-test
 
     - name: Test Libint library - unit tests

export/cmake/CMakeLists.txt.export

@@ -191,8 +191,21 @@ set(LIBINT2_INSTALL_CMAKEDIR "lib/cmake/libint2"
 file(STRINGS "${CMAKE_CURRENT_SOURCE_DIR}/srclist.cmake" LIBINT2_LIBRARY_CXX_SRC ENCODING UTF-8)
 set(LIB_CXX_SRC )
 foreach(FN IN LISTS LIBINT2_LIBRARY_CXX_SRC)
-    message(WARNING "found source file src/${FN}")
-    list(APPEND LIB_CXX_SRC "src/${FN}")
+    set(srcfile "${CMAKE_CURRENT_SOURCE_DIR}/src/${FN}")
+    if (MSVC)
+         string(REGEX REPLACE "[a-zA-Z0-9_.]" "" NONASCII_FN "${FN}")
+         if (NONASCII_FN)
+             message(WARNING "Non-ASCII characters in filename ${FN}")
+             string(MAKE_C_IDENTIFIER "${FN}" C_FN)
+             if (FN STREQUAL C_FN)
+                 message(FATAL_ERROR "Non-ASCII characters in filename ${FN} but C identifier is the same")
+             endif()
+             file(CREATE_LINK "${CMAKE_CURRENT_SOURCE_DIR}/src/${FN}" "${CMAKE_CURRENT_SOURCE_DIR}/src/${C_FN}" SYMBOLIC)
+             message(WARNING "Created symbolic link ${CMAKE_CURRENT_SOURCE_DIR}/src/${C_FN} -> ${CMAKE_CURRENT_SOURCE_DIR}/src/${FN}")
+             set(srcfile "${CMAKE_CURRENT_SOURCE_DIR}/src/${C_FN}")
+         endif()
+    endif(MSVC)
+    list(APPEND LIB_CXX_SRC "${srcfile}")
 endforeach()
 # Create object files to use for static and shared libraries
 add_library(libint2_obj OBJECT ${LIB_CXX_SRC} "src/configuration.cc")