-XPolyKinds causes "*** Exception: Prelude.(!!): index too large"
The following program will compile fine:
{-# OPTIONS_GHC -Wall #-}
{-# Language DeriveFunctor #-}
--{-# Language PolyKinds #-}
module Bug where
data V a = V [a] deriving Functor
data C x a = C (V (P x a)) deriving Functor
data P x a = P (x a) deriving FunctorBut when PolyKinds is enabled, GHC crashes with
$ ghc Bug.hs
[1 of 1] Compiling Bug ( Bug.hs, Bug.o )
Bug.hs:9:37:ghc: panic! (the 'impossible' happened)
(GHC version 7.8.0.20140228 for x86_64-unknown-linux):
Prelude.(!!): index too largeTrac metadata
| Trac field | Value |
|---|---|
| Version | 7.8.1-rc2 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |