Bad error message for non-exhaustive guard
ghci> let (x,y) | False = (1,2) in x
*** Exception: <interactive>:1:5-25: Non-exhaustive guards in
Patch in !6022 (closed).
ghci> let (x,y) | False = (1,2) in x
*** Exception: <interactive>:1:5-25: Non-exhaustive guards in
Patch in !6022 (closed).