Answers from here: https://github.com/Ulauncher/Ulauncher/issues/222
molguin92 commented on Jul 5, 2018 •
Hi! Sorry for necroing this thread, but I found a workaround to this issue.
The problem lies with the /org/gnome/mutter/overlay-key dconf key, which determines the key bound to launch the overview in Gnome Shell and is set to Super_L by default. This is in addition to the default binding of Super+S set in the Keyboard Shortcut settings.
Changing this key to something else (I set it to the right Super key, Super_R) allows the use of the left Super key for launching ULauncher. I've done this for some time now without any adverse effects, and I can still access Gnome Shell's overview through the use of Super + S.
gabrieldrs commented on Oct 3, 2019
Hey, sorry again for bringing this up, but this is one of the first results on google about this issue and @molguin92 solution is not applicable to Ubuntu 19.04.
In order to change the shortcut now you have to install gnome-tweak-tool. Inside it, go to Keyboard & Mouse and there's an option to change the Overview Shortcut to the Right Super.
This indeed fixes the Super + space shortcut problem with ulauncher in gnome.