Comment 24 for bug 1585332

As a note to testers concerning this issue - as observed on 18.04LTS Ubuntu, on ubuntu-session the snaps only follow the installed theme if it is one of the themes preinstalled or from base repos; ie Adwaita(/dark) Ambience or Radiance etc. User installed themes from other repos, in my case Adapta from ppa:tista/adapta, are not applied to snap apps.

Example : https://imgur.com/a/jVBrUre

This is not a uniform bug. Chromium for instance on snap does find the titlebar theme, but not the mouse theme. Gnome Calculator as seen above finds only default theme, but keeps the user choice of mouse pointer just fine.