https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121020
--- Comment #9 from Sam James <sjames at gcc dot gnu.org> --- (In reply to Sam James from comment #8) FWIW, I've checked that this reproduces it in a Debian stable container too (i.e. there's nothing special that the stage1 gcc-trunk/g++-trunk that CC/CXX should point to must be configured with).
