Tested v5.3.0 prealpha 6f434a9, UI is unbearably slow

Builds labeled under Krita 6.0.0 prealpha have normal UI performance and no lag,
however the click with stylus is buggy, with the interface causing the click to repeat
twice for one click.

Consequences :

  • you attempt to select a menu, the menu show and hides
  • you untick a brush option parameter, but once ticked or unticked, you can’t change the state,
    until you click on something else, then click back again;
  • you can not select multiple layers with CTRL or SHIFT for some reason