[CMake] set_target_properties not setting COMPILE_DEFINITIONS?

[David Doria]

I have setup a list of definitions:

SET(MAIN_BUILD_DEFINITIONS "${MAIN_BUILD_DEFINITIONS} UNIX;")
SET(MAIN_BUILD_DEFINITIONS "${MAIN_BUILD_DEFINITIONS} PIXEL_DIMENSION=3;")

I display them and apply them to my executable as follows:

add_executable(ImageCompleter ${MainSources})
message("Main build definitions: " ${MAIN_BUILD_DEFINITIONS})
set_target_properties(ImageCompleter PROPERTIES COMPILE_DEFINITIONS
"${MAIN_BUILD_DEFINITIONS}")

The output is:
Main build definitions:  UNIX PIXEL_DIMENSION=3

which looks correct (i.e. UNIX was defined)

However, in my code there is:

#if defined(UNIX)
	... some code...
#else
#error "Not implemented for this platform!"
#endif

When I build, the error is produced, indicating that UNIX was not defined.

I created a small standalone example and it worked as expected... any
suggestions of what else to check?

Thanks,

David