UBSan: Undefined Behavior in /usr/src/lib/libc/compat/../locale/multibyte.h:75:37, member access within misaligned address 0x7f7ff75be498 for type 'const struct _RuneStatePriv' which requires 16 byte alignment UBSan: Undefined Behavior in /usr/src/lib/libc/compat/../locale/multibyte.h:75:37, load of misaligned address 0x7f7ff75be498 for type '_RuneLocale *const' (aka 'struct _RuneLocale *const') which requires 16 byte alignment Reproducer ---------- ./build.sh -V MKLLVM=yes -V HAVE_LLVM=yes -V MKGCC=no -V MKLIBCSANITIZER=yes distribution mount -t null /dev /path/to/destdir/dev mount -t null /dev/pts /path/to/destdir/dev/pts mount -t null /tmp /path/to/destdir/tmp chroot /path/to/destdir/ cd /usr/tests atf-run