Hi,
I had a problem trying to build PPL with Homebrew on Mac OS X with a Core 2 Duo CPU. I filed a bug with Homebrew here (along with all the output from configure):
https://github.com/mxcl/homebrew/issues/17917
The problem is that the `uname -m` command on this CPU returns the string "i386", but the cc compiler from Xcode 4.6 on Mac OS X doesn't accept the argument "-march=i386". Configure tries to do this:
configure:6759: cc -c -g -O3 -fomit-frame-pointer -march=i386 conftest.c >&5 error: unknown target CPU 'i386' configure:6759: $? = 1
The result is confusing because configure ends up complaining about not finding the GMP library version 4.1.3 or above.
I was able to work around this problem for me by adding "--enable-arch=core2" to the ./configure line, but that's not an ideal solution.
Thanks for looking at this, Frank