https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69495
--- Comment #4 from janus at gcc dot gnu.org --- Btw, I noticed another loosely related issue concerning misspellings of the warning flags: $ gfortran -Wunused-labels test.f90 gfortran: error: unrecognized command line option ‘-Wunused-labels’ $ gfortran -Wno-unused-labels test.f90 (no error!) $ gfortran -Wall -Wno-unused-labels test.f90 f951: Warning: unrecognized command line option ‘-Wno-unused-labels’ This seems very inconsistent: All three calls involve an invalid flag, but the diagnostics is very different for each of them (it's particularly bad that the second case does not give any kind of feedback). Is there a reason for this behavior?