Comment 1 for bug 1484844

UPDATE: As I learn more I have found that casper 1.340.2 is working fine, but that there is no support for mdm, the login manager for Linux Mint. Here is a patch to add that will make it work:

/usr/share/initramfs-tools/scripts/casper-bottom/15autologin:

Add in a MDM section like below:

if [ -f /root/etc/mdm/mdm.conf ]; then
    # Configure MDM autologin
    MDMConfFile=/root/etc/mdm/mdm.conf
    AutomaticLoginParameters="AutomaticLoginEnable=true\n\
AutomaticLogin=$USERNAME\n\
TimedLoginEnable=false"
    # Prevent from updating if parameters already present (persistent usb key)
    if ! $(grep -qs '^AutomaticLogin' $MDMConfFile); then
        sed -i "s/\[daemon\]/\[daemon\]\n$AutomaticLoginParameters/" \
            $MDMConfFile
    fi
fi

With that above addition, casper is "auto logging in" with MDM as the display manager.