Segfaults on levity-polymorphic type class
{-# Language FlexibleInstances, TypeFamilies, TypeInType, MagicHash #-}
import Data.Kind
import GHC.Exts
class Shw (a :: TYPE rep) where
shw :: a -> String
instance Int# ~ a => Shw (a :: TYPE IntRep) where
shw a = "I#" ++ show (I# a)
main = putStrLn (shw 3#)
induces a segfault
$ runghc --version
runghc 8.0.1
$ runghc test.hs
I#Segmentation fault
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |