Replication question

[Mauritz Stenek]

Hi all,

Suppose you have these packages in your environment:

   A@old
   B
   C

where `A` is pinned to the `old` version, which is not in the 
latest channel versions -- as per `guix describe`; the latest 
versions of both `B` and `C`, however, are in the latest channel 
versions but *not* in the channel versions where `A@old` is 
defined.

How, then, is this environment replicable without some hacky 
gymnasitcs?

What am I missing?

--
Mauritz Stenek <mstenek@disroot.org>