I have no idea, frankly :)

I guess my point is that the tool chain was not designed with cross compilation in mind, so sorting out how to make it work and writing a howto is something that needs to be done.  The patches that have already been applied address a narrow need felt and fixed by the Debian folk, dealing with cross compiling 64 bit vs 32 bit, if I understand correctly.  I don't know if it is a general cross compile fix, but in theory it should at least have moved us closer.

Now, that said, as far as build order goes, what we do in general is to check in the sources that are built by the tools.  If you get your sources out of a tarball, make shouldn't try to rebuild those.  If you are working from a checkout, try 'make touch' before the make, to update the timestamps the way they would be in a release tarball.