There was a bootstrap problem with gcc47.
For systems without gcc47 (which is almost all of them), the buildworld
failed on the first gcc47 libraries which require gcc47 to build. The
gnu/lib/gcc47/csu target was duplicated and the makefile was attempting
to build it before gcc47 was installed.
_gcc44_cross= gnu/usr.bin/cc44
_gcc44_tools= gnu/usr.bin/cc44/cc_prep gnu/usr.bin/cc44/cc_tools
.if !defined(NO_GCC47)
-_gcc47_cross= lib/libz gnu/usr.bin/mpc gnu/lib/gcc47/csu gnu/usr.bin/cc47
+_gcc47_cross= lib/libz gnu/usr.bin/mpc gnu/usr.bin/cc47
_gcc47_tools= gnu/usr.bin/cc47/cc_prep gnu/usr.bin/cc47/cc_tools
.endif
_custom_cross= libexec/customcc