Comment 8 for bug 682662

For those trying to non-interactively enable mkhomedir module, here's what I did:

sed -i '/mkhomedir/d' /var/lib/pam/seen
pam-auth-update --package

After running pam-auth-update, mkhomedir was present in /etc/pam.d/common-session. Found this solution here https://ubuntuforums.org/showthread.php?t=2278852