libprocstat compile error

I get this when compiling world with clang (don't know about gcc)

===> libprocstat (depend)
rm -f .depend
CC='clang' mkdep -f .depend -a    -I. -I/usr/src/lib/libprocstat
-D_KVM_VNODE -DZFS -DNDEBUG /usr/src/lib/libprocstat/cd9660.c
/usr/src/lib/libprocstat/common_kvm.c
/usr/src/lib/libprocstat/libprocstat.c
/usr/src/lib/libprocstat/msdosfs.c /usr/src/lib/libprocstat/ntfs.c
/usr/src/lib/libprocstat/nwfs.c /usr/src/lib/libprocstat/smbfs.c
/usr/src/lib/libprocstat/udf.c
/usr/src/lib/libprocstat/nwfs.c:44:10: fatal error: 'fs/nwfs/nwfs.h'
file not found
#include <fs/nwfs/nwfs.h>
         ^
1 error generated.
mkdep: compile failed
*** Error code 1

Stop in /usr/src/lib/libprocstat.
*** Error code 1

Stop in /usr/src/lib.

-- 
chs,