https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103305
--- Comment #3 from Tamar Christina <tnfchris at gcc dot gnu.org> --- logs indicate that this started happening between 3ba1bd0d9dbc..2ec453b566ac on Nov 12. However that range contains a suspicious newlib commit https://github.com/bminor/newlib/commit/3ba1bd0d9dbc015c14a0aaafcef042f706d1249a which changed ctype_.h. So that is likely the culprid.