This error is occurring because sbrk() is deprecated on OSX, -Werror is enabled for the binutils build, and the compiler (in this case “gcc” is an alias for clang) rightly complains about the use of sbrk(). I’ll be looking into eliminating this error this weekend when I won’t have to be at my day job. 😉
I looked into it a bit more. This happened because the latest version of OS X (Mavericks) uses clang as its compiler and /usr/include/unistd.h has a deprecated declaration of sbrk().
The solution was to add a -Wno-error=deprecated-declarations option to the CFLAGS for binutils. I also had to make a few other changes to complete the Max OS build. You can find the latest stuff in the ELLCC subversion tree.