This number scheme starts with darwin 8.4 and then stops with 9.0? I will confirm, but it is darwin 8.0 - 8.3 that I am having problems building on my MacBook.
8.0 - 8.3 were only released as PPC in binary form. Even though they're built with the i386 architecture, the ABI is different from what finally shipped on the MacBook, and the i386 half of the sources were essentially thrown away. In fact, none of the PPC build lineage for 8.x are expected to work on an Intel machine.
So, does that explain why I cannot build any projects prior to 8.4 on my MacBook running OS X? What I infer from this, the only way to build intel version of darwin 8.0-8.3 is to be running an intel version of Darwin 8.0-8.3. (or a ppc version in the same version range) This would also imply that moving from darwin 8.3 to 8.4 would be very tricky (build wise). Michael