Comment 2 for bug 1652441

for anybody wanting to workaround this the generated desktop file is named:
<snap_name>_<app_name>.desktop and placed in /var/lib/snapd/desktop/.
For teatime this requires to change code to search for "teatime_teatime.desktop".

As a solution I think that snapcraft should check that the meta/gui/*.desktop filename is correct instead of snapd generating it. This way me (as a developer) would have a chance to guess what to look for.