Idle detection not functionning on Linux

[CubeTheThird]

Describe the bug
Recently, the boinc client is resulting in errors when attempting to perform idle detection

Steps To Reproduce

1. Enable the suspend when in-use settings
2. Wait

Expected behavior
After a few minutes, idle detection will kick in, resuming e.g. GPU computing

System Information

• OS: Arch Linux
• BOINC Version: 7.16.11
• wxWidgets Version: 3.0.5
• DE: Gnome 3 X11

Additional context
Checking the logs with the idle_detection_debug flag on, this is found in the output:

[idle_detection] Error (2) opening /tmp/.X11-unix/.
[idle_detection] Could not connect to any DISPLAYs. XSS idle determination impossible.

If there are any other relevant logs I can provide, please let me know.

[cminnoy]

I use the following Python script on one of my Ubuntu 20 machines that starts when the machine boots.
It works very well.

#!/usr/bin/python3

import subprocess
import time
import os

while True:
    result = subprocess.check_output(["dbus-send", "--print-reply", "--dest=org.gnome.Mutter.IdleMonitor", "/org/gnome/Mutter/IdleMonitor/Core", "org.gnome.Mutter.IdleMonitor.GetIdletime"])
    result = str(result)
    idle_milli = int(result.split()[-1].strip()[:-3])
    if idle_milli > 3 * 60 * 1000:
#        print("activate\n")
        os.system("boinccmd --set_gpu_mode always 10")
        os.system("boinccmd --set_network_mode always 10")
        os.system("boinccmd --set_run_mode always 10")
    time.sleep(5)

[AenBleidd]

Closed as a duplicate of #1187