Thank you @mzenz for the detailed report. Can you please repeat the same scenario with RUST_BACKTRACE env var set to 1 and provide the backtrace of the error.

export RUST_BACKTRACE=1 
sudo -E /usr/local/bin/kbct remap --config /etc/kbct/config.yml

Even with that variable set as you describe, I get the exact same output as far as I can tell:

 INFO  kbct > Starting kbct event loop, pid=5939
 INFO  kbct > Capturing device path=/dev/input/event2 name="AT Translated Set 2 keyboard" mapped_name="Kbct-AT Translated Set 2 keyboard"
Error: IOError(Os { code: 4, kind: Interrupted, message: "Interrupted system call" })

Below is the output I get if I attach gdb to the process and then repro the bug:

$ gdb --args /usr/local/bin/kbct remap --config /etc/kbct/config.yml

GNU gdb (Ubuntu 11.1-0ubuntu2) 11.1
This GDB was configured as "x86_64-linux-gnu".
(gdb) run
Starting program: /usr/local/bin/kbct remap --config /etc/kbct/config.yml
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff7c5f640 (LWP 9254)]
 INFO  kbct > Starting kbct event loop, pid=9163
[Thread 0x7ffff7c5f640 (LWP 9254) exited]
 INFO  kbct > Capturing device path=/dev/input/event2 name="AT Translated Set 2 keyboard" mapped_name="Kbct-AT Translated Set 2 keyboard"
Error: IOError(Os { code: 4, kind: Interrupted, message: "Interrupted system call" })
[Inferior 1 (process 9163) exited with code 01]

I’ve also stumbled upon this issue. I come with no further information, as I receive the same logs when suspending the computer whilst running KBCT.

However, I wanted to bump this issue and ask whether there are any updates on this?

@jerry-sky my solution was to just have KBCT run as a service via systemctl and configure it to restart automatically if it ends/crashes:

First create the service config file @ /usr/lib/systemd/system/kbct.service with the following content:

[Unit]
Description=KBCT key mapper

[Service]
User=root
WorkingDirectory=/usr/local/bin
ExecStart=kbct remap --config /etc/kbct/config.yml
Restart=always

[Install]
WantedBy=multi-user.target

Then enable KBCT to run at system start:

sudo systemctl enable kbct.service

This assumes that the KCBT executable is installed in /usr/local/bin, your location might vary.

FWIW, I just started noticing this issue occurring much more after switching from Ubuntu 21.10 to 22.04 (Wayland on both installs), tried running with RUST_BACKTRACE=1 and similarly only got Error: IOError(Os { code: 4, kind: Interrupted, message: "Interrupted system call" }).

While I do have kbct setup to run at system start I haven't considered auto-restart yet like the above comment. My workaround so far has been to just keep a restart_kbct.sh script that can easily be invoked from a launcher tool (e.g. pkexec /path/to/kbct remap --config /path/to/my/config.yaml &)