Changing the verbosity of wpa_supplicant on Ubuntu

Sometimes you need to change the log verbosity of wpa_supplicant for debugging purposes. First check which log verbosity you are currently running with.

ps -ef | grep wpa_supplicant | grep -v grep

-d represents verbose
-dd represents extra verbose

To change the log verbosity, edit /usr/share/dbus-1/system-services/fi.epitest.hostap.WPASupplicant.service and add -d or -dd as appropriate. Example:

[D-BUS Service]
Name=fi.epitest.hostap.WPASupplicant
Exec=/sbin/wpa_supplicant -u -d -f /var/log/wpa_supplicant.log
User=root

Restart NetworkManager and run the check again to see which log verbosity you are running with.