We converted our ExternalProject code to use FetchContent_Declare/FetchContent_Populate and allow us to copy files/set args before calling add_subdirectory. This worked very well until the latest version changed restrictions on FetchContent_Populate.
I have tried to change to FetchConent_MakeAvailable without success.
The question is can I copy a file to the downloaded source before MakeAvailable activates?
Allen @ The HDFGroup