grub-set-default should give a warning when GRUB_DEFAULT != saved

[Jordan]

Binary package hint: grub2

Without GRUB_DEFAULT=saved in /etc/default/grub grub-set-default and grub-reboot will silently fail and users are likely to see this as a bug rather than a misconfiguration.

In the simplest case these utilities should should check /etc/default/grub and print a warning that the changes being made will have no effect without GRUB_DEFAULT=saved ( but still make the changes ).

[Daniel Richard G. (skunk)]

Agreed. I was about to file a bug to the effect of "grub-set-default does not work."

Also, the grub-set-default(8) and grub-reboot(8) man pages clearly need to mention this caveat.

[Marcus Tomlinson (marcustomlinson)]

This release of Ubuntu is no longer receiving maintenance updates. If this is still an issue on a maintained version of Ubuntu please let us know.

[Daniel Richard G. (skunk)]

I've confirmed that this issue is still present in Ubuntu focal.

[Daniel Richard G. (skunk)]

To elaborate on the situation in Ubuntu focal, as there have been some improvements:

* grub-reboot(8) now works even when GRUB_DEFAULT != "saved", so that is out of the picture. I've edited the title of this bug accordingly.

* Both the man page and --help text for grub-set-default(8) indicate that GRUB_DEFAULT="saved" is required for the command to have the desired effect.

* grub-set-default(8) still gives no warning/error when GRUB_DEFAULT != "saved", however, leaving open the possibility of breaking scripts or other scenarios where it is assumed to work.