I’m working with Xenko for some months now and it doesn’t feel unfinished to me. In fact, I’m building the engine from source almost every day and I’ve also set up our TeamCity build server to do so. Our customers can even download the custom build of the engine via the official launcher, which is pretty awesome:
So it seems there was something wrong with your build environment. When did you last have look at it? There have been almost 200 pull requests merged since it went open source.
Yes, it takes a while to understand the code, but that is because their systems do abstractions where it’s needed for proper scalability. If it clicks, you would be amazed by the possibilities and how clean it is to extend the engine.
The repo is self-sustained, there is no external lib that would change without someone updating it in the repo. The error messages you posted only mean that you didn’t initialize your git repository with git LFS, since that is required to download the referenced binaries (as stated in the build instructions). You are probably using an old git version without LFS?
Development is very active, the lead developer from Silicon Studio is maintaining the open-source repo. If you want to see an easy example of how to extend the rendering pipeline including editor support, you can find that here: GitHub - tebjan/Stride.CustomRootRenderFeature: Demo implementation of a Stride root render feature that you can use in the graphics compositor
It would be great to see some more people working on it. I’m quite excited about it…