#1008294 grub: Grub doesn't detect another install

Package:
grub2
Source:
grub2
Description:
GRand Unified Bootloader, version 2 (dummy package)
Submitter:
Philip Ashmore
Date:
2022-04-21 00:06:03 UTC
Severity:
important
#1008294#5
Date:
2022-03-26 02:42:03 UTC
From:
To:
Dear Maintainer,

   * What led up to the situation?
I wanted to try Debian bookworm
   * What exactly did you do (or not do) that was effective (or
     ineffective)?
I installed Debian Bookworm onto a second SSD
   * What was the outcome of this action?
The install completed (from a netinst) but after rebooting, my original SSD install (buster) wasn't listed as a boot option in GRUB.
   * What outcome did you expect instead?
I expected that the original install would be listed.
I also expected that an "update-grub" from buster would list bookworm as a boot option - it didn't.
I tried changing the hostname in bullseye from "debian" to "bullseye" in bullseye before running "update-grub" - no cgange.
#1008294#10
Date:
2022-03-26 20:52:03 UTC
From:
To:
I changed the (my current) bullseye host name via
# hostname bullseye

I also changed /etc/hosts and /etc/hostname for the new host name.

I then rebooted into bookworm and ran update-grub again.

No change. I can boot into bullseye because of the modified
/etc/40_custom entry.
It's not secure boot - I disabled it through the "System setup" boot option.

My system is a Dell XPS 8940 desktop.

Curiously, even system setup doesn't list debian bullseye.
I tried to manually add an entry for it but I probably picked the wrong
partition, it's not user friendly.
#1008294#17
Date:
2022-04-21 00:02:00 UTC
From:
To:
It seems that after a recent update, the Bullseye install is visible (a
grub entry is added) in bookworms update-grub.
Bullseye still can't see bookworm when I run its update-grub.

If grub hasn't changed then it's something it uses.

P.S. In a previous email I mentioned "buster" - I meant "bullseye".