Failing monadic pattern matches have confusing error messages
I was just trying to build
basement with GHC head (8.9). I got this error message:
Basement/Block/Base.hs:398:9: error: Not in scope: ‘fail’ Perhaps you meant ‘Data.List.tail’ (imported from Data.List) | 398 | arr@(Block arrBa) <- makeTrampoline | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
For those already in the know, it's pretty easy to discern the meaning of this. But for those who aren't, this message is nonsense.