Interesting examples, thanks! I have to nitpick a bit though. You said "real-world Haskell requires enabling half a dozen language extensions ... some of whic

Interesting examples, thanks! I have to nitpick a bit though. You said "real-world Haskell requires enabling half a dozen language extensions ... some of which are mutually incompatible". 8.6.1 is 5 years old at this point, so the conflict between DeriveAnyClass and GeneralizedNewtypeDeriving is hardly a pertinent example. The conflict between OverloadedLabels and MagicHash is even less of an example, because the average real world Haskeller never uses MagicHash (and rarely OverloadedLabels: I've never used it once in 10 years of professional real world Haskelling).