Impredicativity flag needed more often
I don't know if this is a bug or a deliberate change, but HEAD requires -XImpredicativeTypes for this program while 7.6.3 does not.
{-# LANGUAGE RankNTypes #-}
f :: (forall a. a) -> b
f = undefinedTrac metadata
| Trac field | Value |
|---|---|
| Version | 7.6.3 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler (Type checker) |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |