Kirigami app from docker fails to find Kirigami plugin

I started developing an app using Kirigami. I went to this page and had to install packages. Instead of filling current OS with packages I created a docker image and installed this packages there. I used this docker to build my app. And it works! But I also want to run and debug my app in docker. I figured out how to run UI app in docker and it ran but there is a warning in terminal:
kf.kirigami: Failed to find a Kirigami platform plugin. If I run the app on the host there is not the warning. But if I run it in docker - warning. Also I see the small difference with appearance, so I want to solve this problem. Help, please!

Is there a reason why you want to run and debug it in Docker? It’s only going to make things more complicated :see_no_evil: We don’t ship any applications in Docker (only tools) so I don’t think we can provide much support

The reason, why I use docker for development is that I don’t want to pollute my home OS with libraries for development. And it’s a good way to check if my binary module use something that isn’t installed on host OS. Using docker helps me to checkout different versions of development environment. Moreover, there is Distrobox (that works above the docker) and it also does isolated development environment. So, it’s a good practice to use some isolation.

I use the docker directly because it supports my IDE CLion.

So, let’s back to my question. X Window server (Wayland) runs on my host machine and I threw DISPLAY to docker. But I think it doesn’t matter, just imaging, that you run an app on your host machine and get such a warning. What should you do? An app somehow searches for this plugin and I have no idea how.

I’ll appreciate any information what this plugin is and how to install it.

I ran into the same error message when trying to build and run an application in a Fedora toolbox on Fedora Kinoite. The application would still start but all icons were missing (probably other errors as well which I didn’t notice).

I fixed it with

sudo dnf install @kde-desktop

That’s quite a bit of overkill, though.

So if the error message could print which file is missing or someone knowns which package(s) must be installed, that would be great.

I’d be willing to write a post on how to setup a toolbox for KDE development.

Distrobox would be the better solution for this, we already have a somewhat basic guide for it that mostly Just Works: Get Involved/development/More - KDE Community Wiki