py/usermod.cmake: Add check that any specified USER_C_MODULES exists.

Signed-off-by: Andrew Leech <[email protected]>

Author: pi-anl

py/usermod.cmake

@@ -42,6 +42,12 @@ endfunction()
 # Include CMake files for user modules.
 if (USER_C_MODULES)
     foreach(USER_C_MODULE_PATH ${USER_C_MODULES})
+        # Confirm the provided path exists, show abspath if not to make it clearer to fix.
+        if (NOT EXISTS ${USER_C_MODULE_PATH})
+            get_filename_component(USER_C_MODULES_ABS "${USER_C_MODULE_PATH}" ABSOLUTE)
+            message(FATAL_ERROR "USER_C_MODULES doesn't exist: ${USER_C_MODULES_ABS}")
+        endif()
+
         message("Including User C Module(s) from ${USER_C_MODULE_PATH}")
         include(${USER_C_MODULE_PATH})
     endforeach()