so setup.py invokes clang by default to build fat object files for both

i386

and

x86_64

archs (this may be only on osx). (1) do we support 32-bit architectures? (2) building for both archs invokes an osx utility called

lipo

, which i cannot currently find the source of / a binary for. i'm probably going to have to dig into the distutils source to see how to remove the

-arch i386

from the clang command invoke, because the docs don't seem to assume you want to control that and clang doesn't appear to have a way to remove an arch from the command line (still looking, however). (3) i only figured this out when clang errored out because it couldn't find

lipo

in the compilation sandbox -- it feels sneaky to have created a fat binary without an explicit argument on the command line and it feels like we probably shouldn't be doing it.