Adapting 3d shader instancing example to 2d (running but not visible, possible shader issue)

[phisn]

I am currently trying to use the shader instancing example and adapt it to 2d. My current minimal example can be found here. The program is running and the render function of the custom pipeline is called but there is nothing rendered to the screen. This might be because of the shader itself but I lack knowledge in what the issue could be and how it could be fixed. Any help would be appreciated.

I am using the 0.12.1 version because libraries that I use are not updated yet, but testing the same code (with type fixes) in 0.13.0 doesn't work either.