Why is GCC ignoring ARCHFLAGS in Snow Leopard?

Question

I'm trying to install AMFAST in a virtual_env location based on a dependencies file. I have export ARCHFLAGS="-arch x86_64" in my local .profile, and have confirmed its presence by running env and seeing it listed. However, whenever I run PIP targeting the virtual environment, gcc is set to target i386 and ppc. I've also tried prepending env ARCHFLAGS="-arch i386 -arch x86_64" and env ARCHFLAGS="-arch x86_64" to the PIP command, but gcc always has the flags -arch i386 -arch ppc -arch x86_64. How can I get gcc to read my archflags?

example:

sudo pip install -E ~/Documents/project/project_env -r ~/Documents/project/trunk/django/dependencies.txt`  

output
...

Running setup.py install for amfast  
  building 'amfast.encode' extension  
  gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DTRACE -arch i386 -arch ppc -arch x86_64 -pipe -I/System/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6 -c amfast/ext_src/encoder.c -o build/temp.macosx-10.6-universal-2.6/amfast/ext_src/encoder.o
  /usr/libexec/gcc/powerpc-apple-darwin10/4.2.1/as: assembler (/usr/bin/../libexec/gcc/darwin/ppc/as or /usr/bin/../local/libexec/gcc/darwin/ppc/as) for architecture ppc not installed
  Installed assemblers are:
  /usr/bin/../libexec/gcc/darwin/x86_64/as for architecture x86_64
  /usr/bin/../libexec/gcc/darwin/i386/as for architecture i386
  amfast/ext_src/encoder.c:2121: fatal error: error writing to -: Broken pipe
  compilation terminated.
  lipo: can't open input file: /var/tmp//ccoYlfhN.out (No such file or directory)
  error: command 'gcc-4.2' failed with exit status 1

Answer 1

Most likely the problem is that the ARCHFLAGS environment variable is not being passed through by sudo. By default, some versions of sudo filter out most env variables as a security measure (see man sudo). Try running it this way:

sudo ARCHFLAGS="-arch x86_64" pip install -E ~/Documents/project/project_env -r ~/Documents/project/trunk/django/dependencies.txt`