https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93289
--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> --- (In reply to kargl from comment #1) > It appears to be an undocumented extension. Add -Wall to your command line. I would rather call it a bug :-) The truncation warning is a separate thing. For instance, it (correctly) triggers for the following valid code: print *, [character(len=2) :: "ab", "hjf333"] and it does not trigger for the invalid character(len=*), parameter :: str = "123" print *, [str, "ab"] end (Obviously also not for the valid "[character(len=20) :: "ab", str]".)