> Yes, although in a different place than I expected. Patch below. The
> end result is to ignore the zero length message, getting it delivered
> to the process would involve considerably bigger changes.

Thank you. Yes, that is the case, the network process is no longer shut
down, but the 0-length message isn't picked up. It prints the following:

    Received string (5): "hello"
    Received string (5): "world"

Rather than the expected:

    Received string (5): "hello"
    Received string (0): ""
    Received string (5): "world"

> I was hoping to avoid installing guile :-)

I figured Guile would be the safest option for the developers of GNU
software, rather than requiring Python, Ruby, ...

> The client works, but the server gets me this, which means Iʼm missing
> some bits somewhere:
>     [...]
>     ice-9/boot-9.scm:3300:6: In procedure resolve-interface:
>     no code for module (rnrs bytevectors gnu)

Hm, could be an addition specific to Guile 3. It can be worked around
probably by doing some less efficient string copying.

> Does guile deliver the empty message?

Yes it does.