Upgrading fro -release

[Vinicius Santos <vininim@xxxxxxxxx>]

When I try to 'make buildworld' from current(cvsup'ed) source, I getthe following error:
  /usr/src/usr.bin/basename/basename.c: In function `stripsuffix':  /usr/src/usr.bin/basename/basename.c:100: warning: implicitdeclaration of function    `mbrlen'  /usr/src/usr.bin/basename/basename.c:100: warning: nested externdeclaration of `mbrlen'  cc -O -pipe -mtune=pentiumpro   -Wunknown-pragmas -Wsystem-headers-Wall -W -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith-Wreturn-type -Wcast-qual -Wwrite-strings -Wswitch -Wshadow-Wcast-align -Wchar-subscripts -Winline   -Wnested-exter
ns-Wredundant-decls   -static -o basename basename.o  basename.o(.text+0x16b): In function `stripsuffix':  : undefined reference to `mbrlen'  *** Error code 1
After checking /usr/include/wchar.h and /usr/src/include/wchar.h, onlythe last has the function. Is 'make buildworld' supposed to be using/usr/include one?