https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78532
--- Comment #4 from Matthias Klose <doko at gcc dot gnu.org> --- using the glibc build from Debian unstable, build logs at https://buildd.debian.org/status/package.php?p=glibc see https://buildd.debian.org/status/logs.php?pkg=glibc&arch=sparc64 for the last successful build.