Installing lxml on a Mac OS X 10.6 that has no PPC support (read: Xcode 4)

buildlibxml.diff

diff --git a/buildlibxml.py b/buildlibxml.py
index bfcf3e4..7bf36e5 100644
--- a/buildlibxml.py
+++ b/buildlibxml.py
@@ -284,8 +284,11 @@ def build_libxml2xslt(download_dir, build_dir,
                     })
             else:
                 env.update({
-                    'CFLAGS' : "-arch ppc -arch i386 -arch x86_64 -O2",
-                    'LDFLAGS' : "-arch ppc -arch i386 -arch x86_64",
+                    #'CFLAGS' : "-arch ppc -arch i386 -arch x86_64 -O2",
+                    #'LDFLAGS' : "-arch ppc -arch i386 -arch x86_64",
+                    # For Xcode 4.0
+                    'CFLAGS' : "-arch i386 -arch x86_64 -O2",
+                    'LDFLAGS' : "-arch i386 -arch x86_64",
                     'MACOSX_DEPLOYMENT_TARGET' : "10.6"
                     })
             call_setup['env'] = env

install.sh

# Xcode 4.0 doesn't support PPC so we need to exclude ppc from -arch
curl -O http://pypi.python.org/packages/source/l/lxml/lxml-2.2.8.tar.gz
tar xfzv lxml-2.2.8.tar.gz
cd lxml-2.2.8
vi buildlibxml.py # apply the patch above to fix libxml2/libxslt build
# The following lines are needed to exclude ppc from lxml itself.
export CXXFLAGS="-isysroot /Developer/SDKs/MacOSX10.6.sdk -arch i386 -arch x86_64"
export CFLAGS="-isysroot /Developer/SDKs/MacOSX10.6.sdk -arch i386 -arch x86_64"
python setup.py build --static-deps --libxml2-version=2.7.8  --libxslt-version=1.1.26
python setup.py install

# Note: alternative is to install Xcode 3.2.6 along side Xcode 4
# http://www.cocoabuilder.com/archive/xcode/299924-no-ppc-from-xcode-4.html