swayidle fails to turn on monitors after a while

[tschan]

Please fill out the following:

• Scroll Version:
  scroll version 1.12.3

• swayidle Version
  1.8.0

• Configuration File:

  [...]
  exec swayidle -w \
    timeout 600 'swaymsg "output * power off"' \
      resume 'swaymsg "output * power on"'
  

• Description:
  After an undetermined amount of time (so far it has happened twice, last time in a scroll session that had been running for ~13 hours) moving the mouse or pushing keys on the keyboard will not result in swayidle turning on the monitors again after turning them off due to inactivity.
  When this happens scroll is still running as expected. Logging into another user session in another tty and executing scrollmsg -s /run/user/path/to/socket "output * power on" turns on the monitors as expected. Unfortunately I don't have any debug logs for scroll when this happened yet.
  Restarting swayidle makes it work once with the following log (timeout was triggered by sending USR1 signal to process):

  2025-12-28 23:54:41 - [Line 903] Got timeout
  2025-12-28 23:54:41 - [Line 750] Register idle timeout at 600000 ms
  2025-12-28 23:54:41 - [Line 751] Setup idle
  2025-12-28 23:54:41 - [Line 713] Command: swaymsg "output * power off"
  2025-12-28 23:54:41 - [Line 756] Setup resume
  2025-12-28 23:54:41 - [Line 713] Command: swaymsg "output * power on"
  2025-12-28 23:54:41 - [Line 1078] No config file found.
  2025-12-28 23:54:41 - [Line 463] Using session: /org/freedesktop/login1/session/_31
  2025-12-28 23:54:41 - [Line 621] Enable idle timeouts
  2025-12-28 23:54:41 - [Line 596] Register with timeout: 600000
  2025-12-28 23:54:54 - [Line 943] Got SIGUSR1
  2025-12-28 23:54:54 - [Line 596] Register with timeout: 0
  2025-12-28 23:54:54 - [Line 650] idle state
  2025-12-28 23:54:54 - [Line 146] Cmd exec swaymsg "output * power off"
  2025-12-28 23:54:54 - [Line 172] Spawned process swaymsg "output * power off"
  2025-12-28 23:54:54 - [Line 174] Blocking until process exits
  2025-12-28 23:54:54 - [Line 179] Process exit status: 0
  2025-12-28 23:55:03 - [Line 663] active state
  2025-12-28 23:55:03 - [Line 596] Register with timeout: 600000
  2025-12-28 23:55:03 - [Line 146] Cmd exec swaymsg "output * power on"
  2025-12-28 23:55:03 - [Line 172] Spawned process swaymsg "output * power on"
  2025-12-28 23:55:03 - [Line 174] Blocking until process exits
  2025-12-28 23:55:03 - [Line 179] Process exit status: 0
  

  Subsequent attempts to send that signal produce no further log output and don't seem to do anything.
  I know this report does not have much to go on right now, but I can't recall ever having a comparable problem with og sway. Are there any particular debug steps you can recommend other than starting scroll with debug logging and hoping the problem occurs again?

[dawsers]

My configuration is very similar to yours:

~/.config/swayidle/config

timeout 600 'swaylock -f'
timeout 605 'scrollmsg "output * power off"' resume 'scrollmsg "output * power on"'
timeout 30 'if pgrep swaylock; then scrollmsg "output * power off"; fi' resume 'if pgrep swaylock; then scrollmsg "output * power on"; fi'
before-sleep 'swaylock -f'
lock 'swaylock -f; sleep 5s; scrollmsg "output * power off"'

I haven't had that problem yet. There is nothing scroll does differently compared to sway in this regard, so if it has never happened to you in sway, it could be because of recent changes to both (scroll follows sway-git).

If you want to debug this, I would first compile a debug version of scroll's git version, in case recent changes affect this problem (there was one particular bug affecting monitor disconnects, but probably unrelated) , and I would reduce the timeout to a few seconds so you can let the timeout happen many times hoping one of them triggers the problem.

Edit: One thing that could (or not) be related would be if you have your keyboard and mouse connected to a USB hub in the monitor, and turning off the monitor turns the hub off, but then it would happen every time, I guess.

Edit: There is also a newer version of swayidle than the one you are using, 1.9.0. It contains all the bug fixes of the last three years. Maybe upgrading helps too.