Unable to get rid of guix-past (and unable to pull)

[Gabriel Wicki <gabriel@erlikon.ch>]

Howdy!

So, mysterious things seem to happen on my machines - yes, that's right,
i managed to reproduce the following behaviour.  But see yourself:

Guix pull fails (has guix-past been rebased or force-pushed?)

    gabriel@silvi ~$ guix pull
    Updating channel 'guix' from Git repository at 'https://git.savannah.gnu.org/git/guix.git'...
    Updating channel 'gabber' from Git repository at 'https://git.sr.ht/~gabber/gabber-channel'...
    Updating channel 'nonguix' from Git repository at 'https://gitlab.com/nonguix/nonguix'...
    Updating channel 'guix-gaming-games' from Git repository at 'https://gitlab.com/guix-gaming-channels/games.git'...
    Updating channel 'guix-past' from Git repository at 'https://codeberg.org/guix-science/guix-past.git'...
    guix pull: error: aborting update of channel 'guix-past' to commit f99ada4123de1eadf668d34dac2d726407634549, which is not a descendant of 5fb77cce01f21a03b8f5a9c873067691cf09d057
    hint: This could indicate that the channel has been tampered with and is trying to force a roll-back,
    preventing you from getting the latest updates.  If you think this is not the case, explicitly allow
    non-forward updates.

So i investigate:

    gabriel@silvi ~$ guix describe
    Generation 21	Oct 23 2024 22:56:15	(current)
    guix 5f4ba1c
        repository URL: https://git.savannah.gnu.org/git/guix.git
        branch: master
        commit: 5f4ba1c09fa0fba1ed230b80bae9f6a4d0d2d303
    gabber 20f7905
        repository URL: https://git.sr.ht/~gabber/gabber-channel
        branch: trunk
        commit: 20f7905206826e0d110cab57974b3426683ac814
    nonguix ad966c3
        repository URL: https://gitlab.com/nonguix/nonguix
        branch: master
        commit: ad966c3844385e8f7b60b0dc915f92a1eba47e09
    guix-gaming-games 5762eda
        repository URL: https://gitlab.com/guix-gaming-channels/games.git
        branch: master
        commit: 5762eda50230715555da5beb0f4d06a5456bb5c0
    guix-past 5fb77cc
        repository URL: https://gitlab.inria.fr/guix-hpc/guix-past
        branch: master
        commit: 5fb77cce01f21a03b8f5a9c873067691cf09d057

Weirdly enough, guix-past is not im my channels configuration (which is
managed by guix home):

    gabriel@silvi ~$ cat .config/guix/channels.scm
    (list (channel
            (name 'guix)
            (url "https://git.savannah.gnu.org/git/guix.git")
            (branch "master")
            (introduction
            (make-channel-introduction
                "9edb3f66fd807b096b48283debdcddccfea34bad"
                (openpgp-fingerprint
                "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA"))))
        (channel
            (name 'gabber)
            (url "https://git.sr.ht/~gabber/gabber-channel")
            (branch "trunk"))
        (channel
            (name 'nonguix)
            (url "https://gitlab.com/nonguix/nonguix")
            (branch "master")
            (introduction
            (make-channel-introduction
                "897c1a470da759236cc11798f4e0a5f7d4d59fbc"
                (openpgp-fingerprint
                "2A39 3FFF 68F4 EF7A 3D29  12AF 6F51 20A0 22FB B2D5"))))
        (channel
            (name 'guix-gaming-games)
            (url "https://gitlab.com/guix-gaming-channels/games.git")
            (branch "master")
            (introduction
            (make-channel-introduction
                "c23d64f1b8cc086659f8781b27ab6c7314c5cca5"
                (openpgp-fingerprint
                "50F3 3E2E 5B0C 3D90 0424  ABE8 9BDC F497 A4BB CC7F")))))

And even pulling with explicitly stating the channels file (which i
thought would **only** pull the channels described in said file) fails
pulling guix-past -- which is *not* part of that very file:

    gabriel@silvi ~$ guix pull --channels=!$
    guix pull --channels=.config/guix/channels.scm
    Updating channel 'guix' from Git repository at 'https://git.savannah.gnu.org/git/guix.git'...
    Updating channel 'gabber' from Git repository at 'https://git.sr.ht/~gabber/gabber-channel'...
    Updating channel 'nonguix' from Git repository at 'https://gitlab.com/nonguix/nonguix'...
    Updating channel 'guix-gaming-games' from Git repository at 'https://gitlab.com/guix-gaming-channels/games.git'...
    Updating channel 'guix-past' from Git repository at 'https://codeberg.org/guix-science/guix-past.git'...
    guix pull: error: aborting update of channel 'guix-past' to commit f99ada4123de1eadf668d34dac2d726407634549, which is not a descendant of 5fb77cce01f21a03b8f5a9c873067691cf09d057
    hint: This could indicate that the channel has been tampered with and is trying to force a roll-back,
    preventing you from getting the latest updates.  If you think this is not the case, explicitly allow
    non-forward updates.

Needless to say, `guix-past' is (seemingly) defined nowhere on my
system.

    gabriel@silvi ~$ sudo cat /etc/guix/channels.scm
    (list (channel (name (quote guix)) (url "https://git.savannah.gnu.org/git/guix.git") (branch "master") (introduction (make-channel-introduction "9edb3f66fd807b096b48283debdcddccfea34bad" (openpgp-fingerprint "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA")))))

Any ideas where this is coming from and/or how i can work around this
issue?  Or where /else/ i could look.  Thanks for any input!

gabber