Equality constraint causes ghc panic
I have the following module:
{-# LANGUAGE TypeFamilies #-}
module GhcBug where
newtype (a ~ b) => S a b = S { unS :: a }
Loading this in ghci results in this:
> :l GhcBug
[1 of 1] Compiling GhcBug ( GhcBug.hs, interpreted )
ghc: panic! (the 'impossible' happened)
(GHC version 6.10.4 for x86_64-unknown-linux):
typePrimRep <pred>a{tv a1MH} [tv] ~ b{tv a1MI} [tv]
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
Trac metadata
Trac field | Value |
---|---|
Version | 6.10.4 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | brad.larsen@gmail.com |
Operating system | |
Architecture |