stub: try to avoid have ; replace by list separator (3rd try)

stubs.cmake

@@ -102,16 +102,20 @@ function(GENERATE_STUBS module_path module_name module_install_dir)
   set(ENV_PATH)
   set(optional_args ${ARGN})
   if(WIN32)
-    set(_path $ENV{PATH})
+    # Ton of conflict between path separators, cmake lists separator and
+    # generator expression
     foreach(py_target IN LISTS optional_args)
       if(TARGET ${py_target})
         set(_is_lib
             "$<STREQUAL:$<TARGET_PROPERTY:${py_target},TYPE>,SHARED_LIBRARY>")
         set(_target_dir "$<TARGET_FILE_DIR:${py_target}>")
-        set(_path "$<${_is_lib}:${_target_dir}\\\;>${_path}")
+        set(_target_path "$<${_is_lib}:${_target_dir}>@${_target_path}")
       endif()
     endforeach()
-    set(ENV_PATH PATH=${_path})
+    string(REPLACE ";" "@" _path_cmake $ENV{PATH})
+    set(_path_cmake "${_target_path}${_path_cmake}")
+    string(REPLACE "@" "\;" _path_str ${_path_cmake})
+    set(ENV_PATH "PATH=${_path_str}")
   endif()
 
   add_custom_target(