While trying to import Glibc, swiftc failed with following error:



<module-includes>:1:10: note: in file included from <module-includes>:1:
#include "///usr/include/complex.h"
         ^
///usr/include/complex.h:32:10: error: 'sys/cdefs.h' file not found with <angled> include; use "quotes" instead
#include <sys/cdefs.h>
         ^
<module-includes>:2:10: note: in file included from <module-includes>:2:
#include "///usr/include/libutil.h"
         ^
///usr/include/libutil.h:42:10: error: 'sys/cdefs.h' file not found with <angled> include; use "quotes" instead
#include <sys/cdefs.h>
         ^
<module-includes>:2:10: note: in file included from <module-includes>:2:
#include "///usr/include/libutil.h"
         ^
///usr/include/libutil.h:43:10: error: 'sys/_types.h' file not found with <angled> include; use "quotes" instead
#include <sys/_types.h>
         ^
<module-includes>:2:10: note: in file included from <module-includes>:2:
#include "///usr/include/libutil.h"
         ^
///usr/include/libutil.h:43:10: note: in file included from ///usr/include/libutil.h:43:
#include <sys/_types.h>
         ^
///usr/include/sys/_types.h:32:10: error: 'sys/cdefs.h' file not found
#include <sys/cdefs.h>
         ^
<unknown>:0: error: could not build Objective-C module 'SwiftGlibc'



I'm using swift-3.1.1 in FreeBSD 11.0.