‘guix substitute’ gets stuck when connection goes down
(address . bug-guix@gnu.org)
As noted while debugging https://issues.guix.gnu.org/59784, turning
off networking while ‘guix substitute’ is downloading (be it with
“ifconfig X down” or by physically unplugging the cable) leads it to be
stuck in ‘read’ or ‘recvfrom’ for a long time.
Most likely this can be addressed by setting SO_RCVTIMEO and SO_SNDTIMEO
to a reasonable value on the socket.
Ludo’.