https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85722
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> --- You are building gmp/mpfr in-tree - what versions? __i386__ isn't defined on x86_64 so the issue looks in whatever does those "testcases". The log isn't helpful as it seems to be produced with -jN and isn't part of the libffi testsuite.