Hi Ludo, On Fri, 5 Jun 2020 at 18:17, Ludovic Courtès wrote: > Generally, rebasing does not necessarily implies ‘git gc’, so I think It depends on how "git gc" is configured. Well, I am not a Git specialist but from my understanding of the manual, by default, these unreachable commits are kepts 30 days and then garbage collected. > one has to be unlucky to have the former commit disappear right away, > no? Unluck happens! as Forest Gump said. ;-) > But yeah, I don’t think there’s much we can do. Or perhaps we could > have ‘commit-relation’ report 'unrelated when one of the commits does > not exist, that’d be clearer and more useful than this error. And report a hint. For example, guix pull --switch-generation Cheers, simon