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HardSun

Member

Registered: 2025-07-29

Posts: 41  

Grub Error / Upgrade to Excalibur

Upgraded Daedalus to Excalibur today.

Not sure why this is happening or how i managed to resolve it but the new grub default update puts my machine into a boot loop with a black screen.

Specifically the line in /etc/default/grub

GRUB_DISTRIBUTOR=`( . /etc/os-release && echo ${NAME} )`

Its output...

echo `( . /etc/os-release && echo ${NAME} )`
Devuan GNU/Linux

The fix was to revert it back to lsb-release, devuan excalibur now boots correctly.

GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`

Its output...

echo `lsb_release -i -s 2> /dev/null || echo Debian`
Devuan

Why would this happen?
Anyone experience this?

Last edited by HardSun (2025-11-24 08:22:31)

oleg

Member

Registered: 2025-11-29

Posts: 5  

Re: Grub Error / Upgrade to Excalibur

I'm not sure if this applies to your case, but I also had a black screen due to an unmounted EFI partition.

It was a message that system may no boot:

Setting up grub-efi-amd64 (2.12-9) ...
Installing for x86_64-efi platform.
grub-install: error: cannot find EFI directory.
Failed: grub-install --target=x86_64-efi  
WARNING: Bootloader is not properly installed, system may not be bootable
Generating grub configuration file ...

I used https://www.system-rescue.org/Installin … ory-stick/ that able to boot system with wrong efi, then mount
mount /dev/sda? /boot/efi
and ran update-grub

I.e., before the final step of the system installation, one should check  whether efi is mounted.

Last edited by oleg (2025-12-01 04:51:50)

HardSun

Member

Registered: 2025-07-29

Posts: 41  

Re: Grub Error / Upgrade to Excalibur

No it doesn't apply to my case.
If you were installing what devuan install media were you using?

oleg

Member

Registered: 2025-11-29

Posts: 5  

Re: Grub Error / Upgrade to Excalibur

I upgraded Daedalus to Excalibur through Internet.
It was working system though efi not was mounted, as now too.

HardSun

Member

Registered: 2025-07-29

Posts: 41  

Re: Grub Error / Upgrade to Excalibur

Are you dual or multi booting different linux systems?
It sounds like you may have had the efi mounted to the wrong partition?

My /boot/efi partition was definitely mounted, i was able to chroot into it the upgraded devuan from a live usb and correct the GRUB_DISTRIBUTOR line in
/etc/default/grub and that fixed it. That was the first thing i checked as i was getting a partial grub loading screen and then blackness, then boot loop.

Last edited by HardSun (2025-12-01 05:11:24)

oleg

Member

Registered: 2025-11-29

Posts: 5  

Re: Grub Error / Upgrade to Excalibur

Bios finds efi even it's not mounted and probably passes where it is to Linux, but grub installer not take the info into account.
I have the only linux system.

Last edited by oleg (2025-12-01 05:31:41)

HardSun

Member

Registered: 2025-07-29

Posts: 41  

Re: Grub Error / Upgrade to Excalibur

Its either human error or a grub bug im not sure.
Most likely my human error knowing my inexperience
Glad you got it fixed oleg.

Last edited by HardSun (2025-12-01 05:44:50)

wert

Member

Registered: 2025-10-30

Posts: 8  

Re: Grub Error / Upgrade to Excalibur

Dont put a little bit  more complex "shell snytax"   into that field.

Grub may not have full blown shell snytax parser.
And because it is fragile.

wrt your case: try remove that parenthesis. replace backtits with $( )  proper.
Maybe scope of $NAME problem.

oleg

Member

Registered: 2025-11-29

Posts: 5  

Re: Grub Error / Upgrade to Excalibur

I found the apt log in /var/log/apt in a compressed file called term.log.1.gz. It can show what happened while grub-install (or update) was running.

stargate-sg1-cheyenne-mtn

Member

Registered: 2023-11-27

Posts: 450  

Re: Grub Error / Upgrade to Excalibur

mostly for future forum visitors looking/searching the term "grub"

advisement from the beginning of the file /etc/default/grub:

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

and especially noting the encouragement to visit:

info -f grub -n 'Simple configuration'

even better, the whole thing:

info -f grub

as always, ymmv.

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