Matvey Aksenov

Why not just derive them? It's slightly inconvenient to add orphan instances anytime debug is needed.

Yeah, sorry about this. The SSL error is a red herring; the machine that hosted the images died a while ago. I really should regenerate them sometime.

While I'm sure there's a reason `optparse-applicative` does things this way, I certainly wouldn't want to emulate its `()`. When I write `a b`, I expect for `b` to actually...

I like your workaround in that it clearly separates the case of a failing parser and an entirely missing variable. Maybe this should be provided by the library.

After some experimentation, I believe the problem is unrelated to `4913`, although it may be exacerbated by it; GHCi still gets stuck on `Failed to load interface for`, albeit less...