[SOLVED] Cron: can't open display

sebastian-65 · 2025-07-11 11:18:28

I'm trying hard to prevent getting this error from each user cronjob (cronie) that runs my python scripts.

Methods I've tried:
- putting DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus and DISPLAY=:0 in cron head
- * * * * * env DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus DISPLAY=:0 "path/script.py"
- * * * * * /usr/bin/xuserrun "path/script.py"
- * * * * * "path/script.py" > /dev/null 2>&1 # this denies me a possibility to get other meaningful errors I need to catch
- importing environment from within python scripts

    gui_env_dynamic = {
        'DISPLAY': current_display,  # Dynamic display detection
        'XAUTHORITY': xauthority_file,  # Dynamic XAUTHORITY detection
        'DBUS_SESSION_BUS_ADDRESS': f'unix:path=/run/user/{user_id}/bus',
        'HOME': home,
        'USER': person,
        'LOGNAME': person,
        'PATH': '/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl',
        'XDG_RUNTIME_DIR': xdg_runtime,
        'XDG_SESSION_ID': '1',
        'XDG_SESSION_TYPE': 'x11',
        'XDG_SESSION_CLASS': 'user',
        'XDG_SEAT': 'seat0',
        'XDG_CURRENT_DESKTOP': 'XFCE',
        'XDG_MENU_PREFIX': 'xfce-',
        'XDG_CONFIG_DIRS': '/etc/xdg/xdg-xfce:/etc/xdg',
        'XDG_DATA_DIRS': '/usr/share/xfce4:/usr/local/share:/usr/share',
        'XDG_CONFIG_HOME': xdg_config,
        'XDG_DATA_HOME': xdg_data,
        'XDG_CACHE_HOME': xdg_cache,
        'XDG_VTNR': '2',
        'XDG_SEAT_PATH': '/org/freedesktop/DisplayManager/Seat0',
        'XDG_SESSION_PATH': '/org/freedesktop/DisplayManager/Session0',
        'XDG_SESSION_DESKTOP': 'XFCE',
        'PRIMARY_DISPLAY': 'eDP1',
        'ORIGINAL_XDG_CURRENT_DESKTOP': 'XFCE',
        # GNOME Keyring environment variables
        'GNOME_KEYRING_CONTROL': f'{xdg_runtime}/keyring',
        'GNOME_KEYRING_PID': '',
        'SSH_AUTH_SOCK': f'{xdg_runtime}/keyring/ssh'
    }

.xinitrc contents:

source /etc/X11/xinit/xinitrc.d/50-systemd-user.sh
exec startxfce4

- I've read docs about cron, running GUI apps, env and whatnot, yet still haven't figured it out properly.
- Using both laptop display and external monitor (tried DISPLAY=:0.0 also)

Any idea how to set display right?

Last edited by sebastian-65 (2025-07-11 16:50:41)

karabaja4 · 2025-07-11 12:20:29

Try something like this:

cron

* * * * *    path/run.sh

run.sh

#!/bin/sh

export XAUTHORITY="${HOME}/.Xauthority"
export DISPLAY=":0"

exec path/script.py

The "export" is the key as it passes the environment variables to the child process.

Last edited by karabaja4 (2025-07-11 12:21:14)

sebastian-65 · 2025-07-11 16:34:01

I've found out I had perhaps a garbled .Xauthority file, so I replaced the contents temporary file (from xauth info) and it worked automagically again!

You've definitely shown me the way, thank you stranger!

seth · 2025-07-11 16:42:22

Also https://gist.github.com/AladW/de1c5676d93d05a5a0e1

Please always remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks.

Arch Linux

#1 2025-07-11 11:18:28

[SOLVED] Cron: can't open display

#2 2025-07-11 12:20:29

Re: [SOLVED] Cron: can't open display

#3 2025-07-11 16:34:01

Re: [SOLVED] Cron: can't open display

#4 2025-07-11 16:42:22

Re: [SOLVED] Cron: can't open display

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