https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121709
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed| |2025-08-28 Ever confirmed|0 |1 Status|UNCONFIRMED |NEW --- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> --- cppdefault does: #ifdef PREFIX_INCLUDE_DIR { PREFIX_INCLUDE_DIR, 0, 0, 1, 0, 0 }, #endif There is also LOCAL_INCLUDE_DIR . Plus there is also needing to handle --sysroot= option too.