Making world with gcc41?

[walt]

I put CCVER=gcc41 in make.conf, and I get this error during
make buildworld:

make: don't know how to make
/usr/obj/usr/src/world_i386/usr/src/gnu/lib/gcc41/libstdc++/../libiberty/libiberty.a.

Has anyone else tried gcc41 yet?  Simon?