Hi again!

I just had a cursory look, and my main concern is that maybe exposing
commands is one more thing to learn for the user, and one more step to
run to get a simple file.

Instead, what about doing what system profiles already do with

  /run/current-system/channels.scm
  /run/current-system/configuration.scm

and store the result of the proposed commands directly in
$PROFILE/channels.scm and $PROFILE/manifest-spec.scm, on each profile
upgrade?

We could add a warning comment at the top, explaining the limitations of
these files (that it does not represent the profile faithfully).

Thoughts?

Last, just a nit: what about listing the packages corresponding to the
commented commits next to them?  For instance

--8<---------------cut here---------------start------------->8---
(list
 ;; Note: these other commits were also used to install some of the packages in this profile:
 ;;   "458cb25b9e7e7c954f468023abea2bebb5d8c75b" monolith obs calibre
 ;;   "4969b51d175497bfcc354c91803e9d70542b7113" 0ad augustus
 ;;   "3d85c3ec652feb22824f355538b51e6955ded361" nyxt
 ;; ...
 ;;   "b76b1d3fb65fec98b96a2b4cfa984316dd956a29" tectonic
 (channel
  (name 'guix)
  ...
--8<---------------cut here---------------end--------------->8---

Thanks for working on this, Ludo!

Cheers!

-- 
Pierre Neidhardt
https://ambrevar.xyz/