https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91130
--- Comment #19 from Jakub Jelinek <jakub at gcc dot gnu.org> --- So the first interesting difference appears in the options lto-wrapper.c (run_gcc) emits it seems to me (based on -xlto being the very first option). So I'd do a debugging session of lto-wrapper in both cases on the run_gcc routine, see what options are added to the obstack by append_compiler_options, what are added by append_linker_options, if there are any differences in fdecoded_options/fdecoded_options_count or decoded_options/decoded_options_count etc.
