Shepherd erroring on guix system reconfigure

[B. Wilson]

Hey Guix,

After pulling about an hour ago and attempting to reconfigure, it looks like
shepherd is falling over, even though the reconfigure command finishes:

    activating system...
    The following derivation will be built:
      /gnu/store/3qlfrj7liqzfqpsb156xdh102wjx1n8y-switch-to-system.scm.drv
    
    building 
/gnu/store/3qlfrj7liqzfqpsb156xdh102wjx1n8y-switch-to-system.scm.drv...
    making '/gnu/store/2rc0xbxw343wv3lpzk64mb1ygcwp8337-system' the current 
system...
    setting up setuid programs in '/run/setuid-programs'...
    populating /etc from /gnu/store/czmsdx39r09nmv328xfmj79m1wqiv46n-etc...
    Backtrace:
               4 (primitive-load "/gnu/store/s246zbwm94plbdkqp2l9q493w9v…")
    In ice-9/eval.scm:
       293:34  3 (_ #(#<directory (guile-user) 7f264efb6c80> #<procedu…>))
    In gnu/build/shepherd.scm:
       193:15  2 (_)
    In gnu/build/linux-container.scm:
         62:6  1 (call-with-clean-exit #<procedure 7f264d4b2ac0 at gnu/b…>)
    In shepherd/service.scm:
        776:0  0 (exec-command _ #:user _ #:group _ #:log-file _ # _ # _ …)
    
    shepherd/service.scm:776:0: In procedure exec-command:
    Unrecognized keyword: #:supplementary-groups
    The following derivation will be built:
      /gnu/store/8dd63z1xazl3yzl1clb663p04qx8b4ga-install-bootloader.scm.drv
    
    building 
/gnu/store/8dd63z1xazl3yzl1clb663p04qx8b4ga-install-bootloader.scm.drv...
    guix system: bootloader successfully installed on '(/boot/efi)'
    shepherd: Evaluating user expression (and (defined? (quote transient?)) 
(map (# ?) ?)).
    guix system: warning: exception caught while executing 'start' on service 
'swap-/var/swap/swapfile':
    In procedure swapon: "/var/swap/swapfile": Invalid argument
    guix system: warning: some services could not be upgraded
    hint: To allow changes to all the system services to take effect, you will 
need to reboot.

The last I have reconfigured is about two weeks agod. Any idea what might be
going on and should I expect problems? As you can see, though, the current
generation is booting, and all looks well AFAICT:

    Generation 18       Apr 17 2022 16:01:33    (current)
      file name: /var/guix/profiles/system-18-link
      canonical file name: /gnu/store/2rc0xbxw343wv3lpzk64mb1ygcwp8337-system
      label: GNU with Linux 5.17.2
      bootloader: grub-efi
      root device: label: "root"
      kernel: /gnu/store/fv9xgiksnsck7hkxnmnmd075zndsmpl7-linux-5.17.2/bzImage
      channels:
        guix-past:
          repository URL: https://gitlab.inria.fr/guix-hpc/guix-past
          branch: master
          commit: 972ba34ae42ba32488a396f565dfcbd6d70a7bdd
        guix:
          repository URL: https://git.savannah.gnu.org/git/guix.git
          branch: master
          commit: 0c89fe9e17dc9e628c73959289464ac5f146c7cd
      configuration file: 
/gnu/store/6na7k26p3j8w6f588k8lbsr651xrf9mh-configuration.scm