guix offload, (test returned #<unspecified>)

[Myles English]

Hello,

Two hosts, setup the same as far as I can see, behave differently when
trying to offload builds, any idea how I can get more information on
what the #<unspecified> might indicate?  Looking at
guix/scripts/offload.scm:551 suggests the result is not a string.

$ guix offload test
guix offload: testing 2 build machines defined in '/etc/guix/machines.scm'...
guix offload: 'host1.mydomain.co.uk' is running guile (GNU Guile) 2.0.13
guix offload: 'host2.mydomain.co.uk' is running guile (GNU Guile) 2.0.13
guix offload: Guix is usable on 'host1.mydomain.co.uk' (test returned 
"/gnu/store/883yjkl46dxw9mzykykmbs0yzwyxm17z-test")
guix offload: error: failed to use Guix module on 'host2.mydomain.co.uk'
(test returned #<unspecified>)

/etc/guix/machines.scm:

(list
 (build-machine
  (name "host1.mydomain.co.uk")
  (system "x86_64-linux")
  (host-key "ssh-ed25519 AAAAC3longkeyhere/wm address@hidden")
  (user "myles")
  (private-key
   (string-append (getenv "HOME") "/.ssh/id_rsa")))
  (build-machine
  (name "host2.mydomain.co.uk")
  (system "x86_64-linux")
  (host-key "ssh-ed25519 AAAAC3notherlongkeyhere address@hidden")
  (user "myles")
  (private-key
   (string-append (getenv "HOME") "/.ssh/id_rsa"))))

When trying this:

$ ssh host1.mydomain.co.uk guile -c "'(use-modules (guix config))'"
$ ssh host1.mydomain.co.uk guile -c "'(use-modules (guix config))'"

both succeed, i.e. return nothing.

Thanks,
Myles