NO_TOOLCHAIN not work under CURRENT?

hi,
adding NO_TOOLCHAIN=YES to /etc/make.conf, got this error message:

mkdep -f .depend -a -DCRT_BEGIN -DIN_GCC -DHAVE_LD_EH_FRAME_HDR
-I/usr/src/gnu/lib/csu/../../../contrib/gcc/config
-I/usr/src/gnu/lib/csu/../../../contrib/gcc -I.
-I/usr/src/gnu/lib/csu/../../usr.bin/cc/cc_tools
/usr/src/gnu/lib/csu/../../../contrib/gcc/crtstuff.c
In file included from
/usr/src/gnu/lib/csu/../../../contrib/gcc/crtstuff.c:62:
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:44:20: stddef.h: No
such file or directory
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:45:19: float.h: No
such file or directory
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:76:20: stdarg.h: No
such file or directory
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:79:19: stdio.h: No
such file or directory
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:85:19: errno.h: No
such file or directory
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:92:20: string.h: No
such file or directory
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:93:20: stdlib.h: No
such file or directory
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:94:20: unistd.h: No
such file or directory
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:97:20: limits.h: No
such file or directory
/usr/src/gnu/lib/csu/../../../contrib/gcc/tsystem.h:100:18: time.h: No
such file or directory
mkdep: compile failed
*** Error code 1

Stop in /usr/src/gnu/lib/csu.
*** Error code 1

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

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

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

Stop in /usr/src.

--hwh