On Fri, 21 Oct 2016 11:37:00 +0200
Roel Janssen <roel@gnu.org> wrote:

> Ludovic Courtès writes:
> 
> > Roel Janssen <roel@gnu.org> skribis:
> >  
> >> Ludovic Courtès writes:  
> >
> > [...]
> >  
>  [...]  
> >>
> >> Ah, sorry, I forgot about this.  This makes sense.  But then, what should we
> >> see when we do:
> >>
> >>   guix package --list-generations=42,46
> >>
> >> Should we see:
> >>   Generation 42 ...:
> >>   <full contents>
> >>
> >>   Generation 46 ...:
> >>   <diff with 42>  
> >
> > This one, IMO.  
> 
> The attached patch implements this behavior.  However, because I use
> @code{previous-generation-number} to determine which generation to diff
> with, the following will not provide a diff as expected:
> 
>   guix package --list-generations=42,41,40
> 
> Any ideas on how to fix this?  Otherwise I'll give it another go over
> the weekend.
> 
> Kind regards,
> Roel Janssen

I adapted your patch to hopefully implement the desired behaviour, but
it might need some cleaning up as I'm just getting started learning
scheme.

HANWE

Benz