https://github.com/martinpitt/umockdev/pull/52
https://bugs.gentoo.org/579988

--- a/src/libumockdev-preload.c
+++ b/src/libumockdev-preload.c
@@ -39,6 +39,7 @@
 #include <inttypes.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <sys/inotify.h>
 #include <sys/socket.h>
 #include <sys/ioctl.h>
--- a/src/umockdev-record.c
+++ b/src/umockdev-record.c
@@ -31,6 +31,7 @@
 #include <stdarg.h>
 #include <sys/stat.h>
 #include <errno.h>
+#include <sys/sysmacros.h>
 #include <sys/types.h>
 #include <glib/gstdio.h>
 #include <fcntl.h>
--- a/tests/test-umockdev-vala.c
+++ b/tests/test-umockdev-vala.c
@@ -36,6 +36,7 @@
 #include <unistd.h>
 #include <glib/gstdio.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <gobject/gvaluecollector.h>
 
 #define _g_error_free0(var) ((var == NULL) ? NULL : (var = (g_error_free (var), NULL)))
--- a/tests/test-umockdev.c
+++ b/tests/test-umockdev.c
@@ -29,6 +29,7 @@
 #include <errno.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
+#include <sys/sysmacros.h>
 #include <sys/un.h>
 #include <linux/usbdevice_fs.h>
 #include <linux/input.h>