Building Slicer from /opt directory reports "permission denied" error

Thanks a lot for the swift clarification!

As a suggestion, since it’s not overly common that the build dir interacts with the source dir, may I suggest the following (pseudocode) improvement in the main CMakeLists, to inform the user about the error more easily/quickly? So that error happens right away, not after x hours and in the middle of the log.

if(CMAKE_VERSION VERSION_GREATER "3.21.0") 
   file(COPY_FILE  ${CMAKE_SOURCE_DIR}/README.md ${CMAKE_SOURCE_DIR}/Utilities/Scripts/SlicerWizard/.tmp_txt RESULT result)
   if(NOT result)
      message(ERROR "You need write permissions in the source dir")
   endif()
endif()

Thanks again!

PS: This would also help with: Variable Slicer_WC_LAST_CHANGED_DATE is expected to be defined - #9 by miniminic