Bug#852323: debian-installer: grub-installer not convert root= entry to UUID

[Michael Stone <mstone@debian.org>]

> I'd still expect the installer to DTRT with UUIDs in that case, 
> though. I'm more thinking of a non-standard bootup / custom kernel or 
> similar...

Maybe I'm missing something here? Fire up a current debian netinst 9.2 
iso in a kvm session (no special image or unusual hardware), go through 
an install. On reboot, look at the defult boot entry in grub, note that 
on the kernel command line root=/dev/sda1 (or somesuch) not UUID=X. This 
is very reproducible. In practice this results in an unbootable system 
for a non-expert user if they install from a USB stick that comes up as 
sda (so the grub entry is sdb) and they pull the USB stick out to boot 
into debian. If the kernel command line is manually fixed up, running 
update-grub after boot will create the expected root=UUID=X kernel 
command line.

This is a regression from jessie, for which the exact same sequence of 
commands would result in a grub kernel command line with root=UUID=X 

Mike Stone