Grub2 problem - can only boot to 2 of 3 OS's

[Colin Watson]

On Fri, May 29, 2020 at 11:08:11AM -0500, jim wrote:
> I did have a look at grub.cfg,but frankly don't understand much of what I
> see there. All 3 OS's are mentioned, here is the first mention of Mint18.3
> (the one that doesn't show in the grub menu), if that helps.

The problem is that that particular grub.cfg file is not currently being
read when your computer starts up.  So trying to decode it won't help
you much.

> For a while now when I move from one LTS version to another I have been
> installing the new version next to the current one and then slowly setting
> it up and moving files to it.

Rather you than me, I guess!  I'd find this hopelessly confusing.

> When I was searching for an answer I was mention of Boot-rep[air, is that a
> good solution?

My instinct is that this is more likely to introduce more problems.  It
should be possible to fix this without pulling in third-party tools.

-- 
Colin Watson (he/him)                              [cjwatson at ubuntu.com]