Troubleshooting

So something has gone wrong… what do you do?

When Qtile is running, it logs error messages (and other messages) to its log file. This is found at ~/.local/share/qtile/qtile.log. This is the first place to check to see what is going on. If you are getting unexpected errors from normal usage or your configuration (and you’re not doing something wacky) and believe you have found a bug, then please report a bug.

If you are hacking on Qtile and you want to debug your changes, this log is your best friend. You can send messages to the log from within libqtile by using the logger:

from libqtile.log_utils import logger

logger.warning("Your message here")
logger.warning(variable_you_want_to_print)

try:
    # some changes here that might error
raise Exception as e:
    logger.exception(e)

logger.warning is convenient because its messages will always be visibile in the log. logger.exception is helpful because it will print the full traceback of an error to the log. By sticking these amongst your changes you can look more closely at the effects of any changes you made to Qtile’s internals.

Capturing an xtrace

Occasionally, a bug will be low level enough to require an xtrace of Qtile’s conversations with the X server. To capture one of these, create an xinitrc or similar file with:

exec xtrace qtile >> ~/qtile.log

This will put the xtrace output in Qtile’s logfile as well. You can then demonstrate the bug, and paste the contents of this file into the bug report.

Note that xtrace may be named x11trace on some platforms, for example, on Fedora.