mod-host not responding to commands over control port until feedback port is connected to

[fps]

run the following in this order (this is using BSD netcat):

1. mod-host -p 5555 -f 6666

wait until it has forked..

2. nc localhost 5555

3. in this nc session: add foo 0

step 3 should have produced an error message but nothing happens. try too send any command to mod-host via nc.

4. in another terminal: nc localhost 6666

after step 4 the error to the previous command appears.

5. kill the nc on port 6666

after step 5 mod-host continues to operate over the control port as expected.

this is running mod-host on archlinux-arm (on a raspberry pi 4) from the mod-host-git package:

[alarm@alarmpi mod-host-git]$ mod-host --version
mod-host version: v0.10.6-352-gb70f6e3
source code: https://github.com/moddevices/mod-host

[fps]

Confirmed to happen with a git build on ubuntu 18.04, too..

commit f6ed5c0

[fps]

And also on commit 76ef52d