GDM - how to enable touchpad tap-to-click

Question

I've enabled tap-to-click in Gnome but it doesn't work on GDM.

I tried running dconf-editor as root to modify the setting but to no avail.

I also tried running sudo -u gdm gsettings set org.gnome.desktop.peripherals.touchpad tap-to-click true but I get the following error

(process:16560): dconf-WARNING **: failed to commit changes to dconf: Error spawning command line 'dbus-launch --autolaunch=long-number-here --binary-syntax --close-stderr': Child process exited with code 1

How do I enable tap-to-click on GDM?

Answer 1

You have to export $(dbus-launch) and set the gsettings backend (tested on archlinux with gdm 3.18.2):

1. switch to a VT (e.g. Ctrl+Alt+F3), login as root and run:

   su - gdm -s /bin/sh
   

   to switch user to gdm.

2. then run:

   export $(dbus-launch)
   

   and:

   GSETTINGS_BACKEND=dconf gsettings set org.gnome.desktop.peripherals.touchpad tap-to-click true
   

   run exit or hit Ctrl+D to return to root account.

3. restart the display manager:

   systemctl restart gdm
   

Reverting is pretty much the same, just change true to false @ step 2.