{code}
# Resolve the architecture
if [ "$DIST_OS" = "macosx" ]
then
    OS_VER=`sw_vers | grep 'ProductVersion:' | grep -o '[0-9]*\.[0-9]*\.[0-9]*'`
    DIST_ARCH="universal"
    if [[ "$OS_VER" < "10.5.0" ]]
    then
        DIST_BITS="32"
    else
{code}

On Mac OS X 10.8 it reports:
{code}
minimac08:~ labuser$ sw_vers
ProductName: Mac OS X
ProductVersion: 10.8.4
BuildVersion: 12E55
{code}

However, on Mac OS X 10.9 the version only consists of major and minor number:
{code}
minimac09:~ labuser$ sw_vers
ProductName: Mac OS X
ProductVersion: 10.9
BuildVersion: 13A603
{code}