This backports part of an upstream patch upstream to make it build with glibc 2.27
The upstream commit is:
commit faade020043cd40cc7b89594ab1cf32e75f2f544
Author: Ken Robertson <ken@invalidlogic.com>
Date:   Wed Nov 8 11:25:38 2017 -0800

    Updated to support changes in glibc
    
    This applies a few fixes for compatibility with glibc 2.24 and 2.25. We're
    building seismograph on some other Gentoo systems to use cgpt and hit this issue
    recently after a full rebuild since upstream Gentoo recently marked glibc 2.25
    stable.
    
    glibc 2.24 added errors when use `makedev`, `major`, `minor` when included from
    `sys/types.h`. The definitions have been moved to `sys/macros.h` and are
    resolevd just by including it.
    
    glibc 2.24 deprecated `readdir_r`, and glibc 2.25 made its use an error. glibc
    implements `readdir` as thread-safe and recommends it over `readdir_r.

diff --git a/src/cgpt/blkid_utils.c b/src/cgpt/blkid_utils.c
index 0340be3..4d35ff2 100644
--- a/src/cgpt/blkid_utils.c
+++ b/src/cgpt/blkid_utils.c
@@ -9,6 +9,7 @@
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <unistd.h>
 
 #include "cgpt.h"