>> It seems that this sort-of inlines parts of ‘shepherd-service-upgrade’
>> but without traversing the service dependency graph to determine the
>> compilete set of obsolete services, no? I feel that we should be
>> reusing ‘shepherd-service-upgrade’ or similar bits. (I realize this is
>> already in ‘master’ for ‘guix deploy’, but since this is going to be
>> shared with ‘guix system’, we’d rather be extra cautious.)
>
> Does 'live-service-requirement' not encompass the full service
> dependency graph? Regardless, I'll look into reusing
> 'shepherd-service-upgrade' as it's well-testsed.

‘live-service-requirement’ gives you the graph of the currently loaded
services, but you also need the target service graph to determine what
to upgrade; that seems to be missing currently.

Thanks,
Ludo’.