https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61081
--- Comment #8 from Manuel López-Ibáñez <manu at gcc dot gnu.org> --- (In reply to Peter Eisentraut from comment #2) > No, these "functions" need to have a usable return value, because someone > could write > > if (!sigemptyset(...)) > weirderror(); Note that just using: (void) sigemptyset(); silences the warning in those cases where you want to ignore the return value, which could be useful while someone comes up with a patch for a more permanent fix. Or you can use -Wno-unused-value for now.