https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86856
--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to nightstrike from comment #0) > When building the compiler to target x86_64-w64-mingw32, the warnings listed > below appear. I tried making them be %zu instead of %z, but that didn't > help. Maybe it has something to do with the special printf / mingw_printf > on windows targets? Does this happen during stage1? Otherwise, these specifiers are listed in c-family/c-format.c, so the compiler should know about them, see asm_fprintf_char_table.