I've recently been asked whether it was possible for me to convert my older theme contributions to the new Qooxdoo packaging system. So I installed Qooxdoo 6.0 and got a first test app running - not without problems because the instructions in the official docs are a bit buggy (e.g "npx qx" is an unknown command with my Ubuntu 18.04). I also read about the packaging system and what to do to install one of the existing packages from the Qooxdoo repository.
Then I followed the steps described in section "Create a new package". This procedure resulted in a folder structure which looked familiar at first sight, but a closer look made me wonder: There are two resource folders now, one is under "source" (as I would have expected) and the other one is under "source/class/[mypackage]". I also noticed that there is a "demo" folder in "source/class/[mypackage]", which used to be a top-level folder in previous Qooxdoo versions.
I then copied the theming files of my contribution to "source/class/theme", the demo app files to "source/class/[mypackage]/demo" and the demo resources to "source/class/[mypackage]/resource". After compiling the project I managed to run the demo app, but only without the expected resources (no icons, no fonts, no background images). The theming as such appears to be applied properly, but I keep getting plenty of error messages telling me "404 (Not found)" and "Image could not be loaded".
What am I doing wrong?