Pass optional arguments to `ExternalProject_Add` using a variable

Hi CMake folks,
we have a case in ITK where we would like to pass some additional arguments to the ExternalProject_Add command depending on the CMake version:

The approach does not seem to work: CMake does not understand as we had expected the passed extra arguments:

Any guess/suggestion of what I may be missing?


Use set(download_extract_timestamp_flag DOWNLOAD_EXTRACT_TIMESTAMP FALSE). The quoting here causes EP to see a single DOWNLOAD_EXTRACT_TIMESTAMP FALSE argument which has no meaning to it.

Worked like a charm. Thanks Ben !