I think most smaller Wayland compositors are using a library (wlroots, smithay) for most (?) of the compositing. If using a library provides a few extra options

I think most smaller Wayland compositors are using a library (wlroots, smithay) for most (?) of the compositing. If using a library provides a few extra options, while still allowing sharing code, it feel like the API boundary was put in the right place. When there was the 90deg off bug, was that a bug in the compositor or in wlroots?