Ah ok, thanks, for clearing that up, Freak.
It indeed used to be a useful option, and I used it on a bunch of sourcefiles created with 4.31,
thus, there was no project there for them, and the help file is a bit - may I say : - vague on the
fact, that it is confined to IDE compile/run.
Given that projects now are included in the IDE, I think this solves the "problem".
It was just irritating to have set the option on an include which actually compiles fine to an exe,
which, then actually did "nothing" when it was executed
BTW: Thanks to Bluenzl also for trying...