bug#31824: guix offload test fails when the remote daemon uses --debug

[Maxim Cournoyer]

Hello,

I don't know if it is worthy of reporting, but I discovered the
following crash when attempting to use the '--debug' argument on the
remote guix-daemon process and issuing 'guix offload test' on my local
machine:

--8<---------------cut here---------------start------------->8---
guix offload test
guix offload: testing 1 build machines defined in '/etc/guix/machines.scm'...
guix offload: '192.168.1.105' is running guile (GNU Guile) 2.2.3
guix offload: error: remove evaluation on '(Evaluation failed 
scheme@(guile-user)> ERROR: In procedure display:
In procedure display: Wrong type argument in position 2: #<closed: file 
1186e00> ())' failed:
FORMAT: error with call: (format #<output: file /dev/pts/1> "~:[~*~;guix ~a: 
~]~aremove evaluation on '~a' failed:~{ ~s~}<===~%" offload offload error:  
(Evaluation failed scheme@(guile-user)> ERROR: In procedure display:
In procedure display: Wrong type argument in position 2: #<closed: file 
1186e00> ()) ===>)
        missing argument(s)
Backtrace:
          11 (apply-smob/1 #<catch-closure 2253640>)
In ice-9/boot-9.scm:
    705:2 10 (call-with-prompt _ _ #<procedure default-prompt-handle…>)
In ice-9/eval.scm:
    619:8  9 (_ #(#(#<directory (guile-user) 2308140>)))
In guix/ui.scm:
  1501:12  8 (run-guix-command _ . _)
In ice-9/boot-9.scm:
    829:9  7 (catch srfi-34 #<procedure 2764040 at guix/ui.scm:552:…> …)
    829:9  6 (catch system-error #<procedure 2764060 at guix/script…> …)
In guix/scripts/offload.scm:
    637:6  5 (check-machine-availability _ _)
In srfi/srfi-1.scm:
   656:11  4 (for-each #<procedure assert-node-has-guix (node name)> …)
In guix/scripts/offload.scm:
    579:6  3 (_ _ . _)
In ice-9/format.scm:
  1590:19  2 (format #<output: file /dev/pts/1> "~:[~*~;guix ~a: ~]…" …)
   197:20  1 (format:format-work "~:[~*~;guix ~a: ~]~aremove evalua…" …)
In unknown file:
           0 (scm-error misc-error #f "~A" ("error in format") #f)

ERROR: In procedure scm-error:
error in format
--8<---------------cut here---------------end--------------->8---

If I remove the --debug option, it still fails, but this is another bug:

--8<---------------cut here---------------start------------->8---
guix offload test
guix offload: testing 1 build machines defined in '/etc/guix/machines.scm'...
guix offload: '192.168.1.105' is running guile (GNU Guile) 2.2.3
guix offload: Guix is usable on '192.168.1.105' (test returned 
"/gnu/store/883yjkl46dxw9mzykykmbs0yzwyxm17z-test")
sending 1 store item to '192.168.1.105'...
exporting path `/gnu/store/3y6882jwsjc76bfv51j037dvyx5p99w3-export-test'
guix offload: error: build failed: program `guix-authenticate' failed
with exit code 1
--8<---------------cut here---------------end--------------->8---

Thanks,

Maxim