Fix python.org uiversal 2 python 3 packages so they don't trigger Rosetta 2 installs on Apple silicon

arch_fix.sh

#!/bin/zsh
function cleanup {
    if [ ! -z "$TMPD" ]; then
        rm -rf "$TMPD"
    fi
}

trap cleanup EXIT

if [ "$#" -eq 0 ]; then
   echo "usage: arch_fix /path/to/python.pkg /path/to/save.pkg"
   exit 0
fi
if [ "$#" -ne 2 ]; then
    echo "error: missing argument(s)\n"
    echo "usage: arch_fix /path/to/python.pkg /path/to/save.pkg"
    exit 1
fi 

# make a temporary directory to unpack to
TMPD=`mktemp -d`

# for sanity's sake, remove quarantine/extended attributes from package just in case
xattr -c "$1"
# expand the output to tmp
pkgutil --expand "$1" "${TMPD}/out"
# patch the Distribution file <options> to include architecture
sed -i '' 's/<options /<options hostArchitectures="x86_64,arm64" /g' "${TMPD}/out/Distribution"
# flatten the package back to the destination
pkgutil --flatten "${TMPD}/out" "$2"