with glibc 2.27
emerge-samus udev

../systemd-225/src/basic/util.c:3570:56: error: implicit declaration of function 'major' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
        if (asprintf(&p, "/sys/dev/block/%u:%u/queue", major(d), minor(d)) < 0)