Hey,

I gave setting up offloading another go, I'm testing with 3 machines,
two running GuixSD, and one Debian. I've tried setting up offloading
from both GuixSD machines to the Debian machine, and from one GuixSD
machine to the other.

Running `guix offload test` works, and reports success. However, when
it actually comes to building something, guix repeatedly prints a
message like:

  "process ... acquired build slot '/var/guix/offload/.../0"

I've left it for a while, and nothing happened.

My usual approach at sticking more logging in to the code doesn't
really work, as it appears that it's not the offload script from the
Guix git repository that I have locally that is being used.

I'm happy to do some more investigation, but I haven't worked out how
to yet.