deriving instance Data (a->b) leads to 'impossible' error instead of "can't do" message
$ cat Data.hs
{-# OPTIONS_GHC -fglasgow-exts #-}
import Data.Generics(Data)
deriving instance (Data a,Data b) => Data (a->b)
$ ghc --make Data.hs
[1 of 1] Compiling Main ( Data.hs, Data.o )
Data.hs:4:0:ghc.exe: panic! (the 'impossible' happened)
(GHC version 6.9.20080514 for i386-unknown-mingw32):
newTyConEtadRhs ghc-prim:GHC.Prim.(->){(w) tc 3D}
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
Trac metadata
Trac field |
Value |
Version |
6.9 |
Type |
Bug |
TypeOfFailure |
OtherFailure |
Priority |
normal |
Resolution |
Unresolved |
Component |
Compiler |
Test case |
|
Differential revisions |
|
BlockedBy |
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Related |
|
Blocking |
|
CC |
|
Operating system |
Unknown |
Architecture |
Unknown |