Swapfile incorrectly set up when installing Bionic from iso

I needed to do an 'emergency' reinstall while travelling owing to a hopeless corrupted encryptfs. I happened to have a Bionic iso from March 11 and used that to install to my laptop.

Soon after installing, I noticed various problems with logins, hangs, etc. which I recently tracked down to the swapfile not being correctly installed. In particular, I selected encrypted home directory (and swap). The installer make a swap file as /swapfile but entered:

cryptswap1 /target/swapfile /dev/urandom swap,offset=1024,cipher=aes-xts-plain64

but of course there is no /target/swapfile. Must be some incomplete set up here? You can see the confusion in the attached syslog.

Also, I have a swap partition preexisting, but I don't recall the installer asking me about setting up a swap partition. When I released swap was missing, I set that up by hand.

Anyway, my bad for not checking swap sooner, but it would be good to check this to prevent some new Ubuntu user from having to rediscover this problem later.