bug#22629: Towards a new 'guix pull'

[Ludovic Courtès]

Hello!

Here’s a series of improvements that I think we should make in ‘guix
pull’:

  • Use Git instead of downloading a whole snapshot every time.  The Git
    checkout would be kept in ~/.cache/guix/pull/checkouts, say.

    A related question is whether to use Git itself, which is pretty big
    per ‘guix size’, or to use some libgit2 bindings such as
    <https://git.dthompson.us/guile-git.git> (the closure of libgit2 is
    435 MiB; that of Git is 761 MiB.)

  • Build & install not only Scheme code, but also locales and the Info
    manual.

  • Have a “channel” mechanism, similar to ‘nix-channel’, that would
    allow users to have several Guix variants available in parallel
    instead of just “latest”.  Could work like this:

      guix channel add latest git://git.sv.gnu.org/guix.git master
      guix channel add stable git://git.sv.gnu.org/guix.git stable
      guix channel pull latest
      guix channel set latest
      # here i see the latest versions of everything
      guix channel set stable
      # and here everything is old but super stable ;-)

All 3 items can be done separately, I think.

Any takers?  :-)

Ludo’.

PS: I do not mention the issue of authenticating code here, which is
    obviously very important and deserves to be treated separately.
    Related to that is the question of making sure that what you think
    is the latest version really is the latest version.  We need someone
    to sign certificates saying what the latest commit ID of a repo is.
    See the “The Update Framework” paper!