preseed raid->lvm->crypto

[shawn wilson <ag4ve.us@gmail.com>]

I see how to create raid devices:
d-i partman-auto-raid/recipe string \
  1 2 0 ext2 /boot
    /dev/sda1#/dev/sdb1
  1 2 0 lvm -
    /dev/sda2#/dev/sdb2

And then making lvm or crypto devices seems easy enough. However, how
do I create one on top of the other (I'd prefer luks inside lvm so
that swap can have a random key but either way works).

Also, on an existing install with a configuration like how I want it:
# debconf-get-selections --installer > ~/preseed-komp.txt
# grep -i error preseed-komp.txt | grep -i error | wc -l
179

So, why is this erroring in so many places?