https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66249
--- Comment #2 from Eric Gallager <egallager at gcc dot gnu.org> --- (In reply to Marek Polacek from comment #1) > -Wformat-signedness has many issues (which was the reason it's been pulled > out of -Wformat=2). Maybe it's time for a -Wformat=3?
