Isn't the solution there for Wine to be printing vkd3d-shader errors as ERR? I thought I remembered a discussion specifically about this before.
Yes. My plan is essentially to wait for DXIL development to settle down a bit, and then do some cleanup to do just that, although I'd use WARN instead of ERR/FIXME. (I.e., errors in the input shader are generally not errors in vkd3d-shader.)