It looks like it might be related to the fact there there isn't a
linux-signed-image-4.4.0-143-generic available? I was able to force it to use
the 142 image by setting:
d-i base-installer/kernel/image string linux-image-4.4.0-142-generic
I could set the parameter preseed-kernel-image to linux-
I'm currently using Foreman to provision machines. I've updated the
image to pull from xenial-updates, but now the installer is unable to
install the base system (the latest linux-headers-4.4.0-143). It's
specifically unable to find the linux-headers-signed-generic. I did not
have this issue
