jnethack-1.1.5 コンパイル、できません。仕様は、FreeBSD 6.2R です。

[umiboz@marine ~/jnethack-1.1.5]$ make
( cd src ; make )
touch ../include/vmsconf.h
----x----x-----x----x-----x---------
from ../include/config.h:542,
from monst.c:5:
/usr/include/string.h:90: error: conflicting types for 'strlen'
/usr/include/string.h:90: error: conflicting types for 'strlen'
*** Error code 1

Stop in /usr/home/umiboz/jnethack-1.1.5/src.
*** Error code 1

Stop in /usr/home/umiboz/jnethack-1.1.5.