I wrote:

>   FWIW, I've tried all communication styles this morning, and none of
>   them work. :SPAWN hangs, and the other ones lead to the exact same
>   error as with :SIGIO (the one I used without even knowing it as it
>   is the default).

  Now I've bisected some recent commits, and I found the culprit. Before
  this one, everything works fine.

commit 2e7f94633acebd5cf4074ce9601b021624ad8233
Author: Stas Boukarev <stassats@gmail.com>
Date:   Thu Jan 11 15:29:00 2018 +0300

    More energy efficient auto-flush-loop.

    Don't spin until there's something to flush.



--
Resistance is futile. You will be jazzimilated.

Lisp, Jazz, Aïkido: http://www.didierverna.info