proftp설치시 에러 문제입니다. ㅡ.ㅡ;

make install clean
===> Building for proftpd-1.2.2rc3
cd lib ; gmake lib
gmake[1]: 들어감 `/usr/ports/ftp/proftpd/work/proftpd-1.2.2rc3/lib' 디렉토리
gmake[1]: Nothing to be done for `lib'.
gmake[1]: 나감 `/usr/ports/ftp/proftpd/work/proftpd-1.2.2rc3/lib' 디렉토리
cd src ; gmake src
gmake[1]: 들어감 `/usr/ports/ftp/proftpd/work/proftpd-1.2.2rc3/src' 디렉토리
gmake[1]: Nothing to be done for `src'.
gmake[1]: 나감 `/usr/ports/ftp/proftpd/work/proftpd-1.2.2rc3/src' 디렉토리
cd modules; gmake modules
gmake[1]: 들어감 `/usr/ports/ftp/proftpd/work/proftpd-1.2.2rc3/modules' 디렉토리
cc -DFREEBSD4_3 -DFREEBSD4 -I.. -I../include -O -pipe -Wall -c mod_linuxprivs.c
In file included from mod_linuxprivs.c:58:
../contrib/libcap/include/sys/capability.h:86: syntax error before`cap_size'
../contrib/libcap/include/sys/capability.h:86: warning: type defaults to `int' in declaration of `cap_size'
../contrib/libcap/include/sys/capability.h:86: warning: data definition has no type or storage class
../contrib/libcap/include/sys/capability.h:87: syntax error before `cap_copy_ext'
../contrib/libcap/include/sys/capability.h:87: syntax error before `ssize_t'
../contrib/libcap/include/sys/capability.h:87: warning: type defaults to `int' in declaration of `cap_copy_ext'
../contrib/libcap/include/sys/capability.h:87: warning: data definition has no type or storage class
../contrib/libcap/include/sys/capability.h:92: syntax error before `ssize_t'
../contrib/libcap/include/sys/capability.h:101: syntax error before `header'
../contrib/libcap/include/sys/capability.h:102: syntax error before `header'
../contrib/libcap/include/sys/capability.h:103: syntax error before `pid'
../contrib/libcap/include/sys/capability.h:104: syntax error before `pid'
mod_linuxprivs.c: In function `lowerprivs':
mod_linuxprivs.c:167: `CAP_NET_BIND_SERVICE' undeclared (first use in this function)
mod_linuxprivs.c:167: (Each undeclared identifier is reported only
once mod_linuxprivs.c:167: for each function it appears in.)
gmake[1]: *** [mod_linuxprivs.o] 오류 1
gmake[1]: 나감 `/usr/ports/ftp/proftpd/work/proftpd-1.2.2rc3/modules' 디렉토리
gmake: *** [modules] 오류 2
*** Error code 2