https://bugs.gentoo.org/251684

--- autorun.cc
+++ autorun.cc
@@ -90,6 +90,8 @@ char *strchr (), *strrchr ();
 
 #include <errno.h>
 
+#include <stdlib.h>
+
 #ifndef MNTTYPE_ISO9660
 #define MNTTYPE_ISO9660 "iso9660"
 #endif