Apples Xcode4 removes the assembler for PPC, yet most applications where not recompiled against this. Example would be Python
/usr/bin/python: Mach-O universal binary with 3 architectures
/usr/bin/python (for architecture x86_64): Mach-O 64-bit executable x86_64
/usr/bin/python (for architecture i386): Mach-O executable i386
/usr/bin/python (for architecture ppc7400): Mach-O executable ppc
Python compiles C extensions with the same compiler flags that Python itself was compiled with. The next version of OS X (Lion) will not have Python built with PPC, which resolves this issue.
To help avoid this problem in the future the following patch changes the default GOARCH from older amd64 type to x86_64 and modifies the python client makefile to pass GOARCH as an -arch flag to setup.py. Tested on os x and centos.
Can someone with windows test this please