bug#55399: guix system reconfigure fails on channel validation

[André Batista]

Hello Guix!

Recently, I've not been able to reconfigure some of my guix systems
because guix fails to forward validate the commits in between the
current system deployment and the newer one. This appears to be
related to the new libgit2 version 1.4.3[1][2], which addressed CVE
2022-24765, since there was no change to the related guix routines
on the time lapse since the last deploy.

This is the error I'm getting:

$ sudo guix system --fallback -c 3 -M 3  reconfigure myconfig.scm
Backtrace:
          19 (primitive-load "/home/user/.config/guix/current/bin/g?")
In guix/ui.scm:
   2230:7 18 (run-guix . _)
  2193:10 17 (run-guix-command _ . _)
In ice-9/boot-9.scm:
  1752:10 16 (with-exception-handler _ _ #:unwind? _ # _)
In guix/status.scm:
    829:3 15 (_)
    809:4 14 (call-with-status-report _ _)
In guix/scripts/system.scm:
   1253:4 13 (_)
In ice-9/boot-9.scm:
  1752:10 12 (with-exception-handler _ _ #:unwind? _ # _)
In guix/store.scm:
   658:37 11 (thunk)
   1320:8 10 (call-with-build-handler #<procedure b445f18 at guix/u?> ?)
  2129:25  9 (run-with-store #<store-connection 256.99 b0934d8> _ # _ ?)
In guix/scripts/system.scm:
  1277:15  8 (_ _)
    819:5  7 (perform-action reconfigure #<<image> name: #f format:?> ?)
In guix/scripts/system/reconfigure.scm:
    345:3  6 (check-forward-update _ #:current-channels _)
In srfi/srfi-1.scm:
   691:23  5 (filter-map #<procedure ba4c460 at guix/scripts/syst?> . #)
In guix/scripts/system/reconfigure.scm:
   352:37  4 (_ #<<channel> name: guix url: "/src/guix.git" branch: ?>)
In guix/git.scm:
    469:7  3 (update-cached-checkout _ #:ref _ #:recursive? _ # _ # _ ?)
In git/bindings.scm:
     77:2  2 (raise-git-error _)
In ice-9/boot-9.scm:
  1685:16  1 (raise-exception _ #:continuable? _)
  1685:16  0 (raise-exception _ #:continuable? _)

ice-9/boot-9.scm:1685:16: In procedure raise-exception:
Git error: repository path '/src/guix.git/' is not owned by current user


-----

And these are the commits being compared:

$ guix system describe
Generation 214  May 06 2022 22:47:43    (current)
  file name: /var/guix/profiles/system-214-link
  canonical file name: /gnu/store/b0wrzz8sxqi9hywpqz29cm73l9adxjy9-system
  label: GNU with Linux-Libre-Atom 5.17.5
  bootloader: grub
  root device: label: "rootfs"
  kernel: 
/gnu/store/xmdskyk85sypr4wgf5iwg5iid08l4aiq-linux-libre-atom-5.17.5/bzImage
  channels:
    guix:
      repository URL: /src/guix.git
      branch: master
      commit: ee70ed5bf50e781a6a43985211aa763e28db62b9
  configuration file: 
/gnu/store/g653hksfz0iwnbpynaq2mx4nv7ayb7r7-configuration.scm


$ guix describe
Generation 200  May 12 2022 13:48:01    (current)
  guix a1cb645
    repository URL: /src/guix.git
    branch: master
    commit: a1cb645d83d085382eaf64f4c097642aa47c297a

Any thoughts?

1. https://github.com/libgit2/libgit2/blob/v1.4.3/docs/changelog.md
2. 
https://github.com/libgit2/libgit2/commit/0cc4a70db0942f65528f4877be14a6a987fe3c64
3. https://github.blog/2022-04-12-git-security-vulnerability-announced/