Kickstart: How log and view %post? Method works in CentOS 5 but not CentOS 7

[therbur]

The following method has worked for years with CentOS 5, to allow
live viewing of %post output and also logging it.  It doesn't
work in CentOS 7.  What is the recommended method now?

# from kickstart text mode install

%post --erroronfail

chvt 3
exec < /dev/tty3 > /dev/tty3 2> /dev/tty3

tail -F /root/ks-post.log &
(

echo "Starting post-kickstart ..."

# ... various commands

echo "Done."
echo
echo "Do Alt-F1 and press Enter to reboot"

) >> /root/ks-post.log 2>&1

%end