Standalone deriving of NFData causes panic
Using the -XStandaloneDeriving option, I tried to generate an NFData instance for the CNF type from the funsat 0.60 package on Hackage.
{-# LANGUAGE StandaloneDeriving #-}
module Broken where
import Funsat.Types
import Control.Parallel.Strategies
deriving instance NFData ASTWith ghc 6.12.1 on 32-bit Ubuntu, the above causes a panic:
ghc: panic! (the 'impossible' happened)
(GHC version 6.12.1 for i386-unknown-linux):
genDerivBinds: bad derived class
deepseq-1.1.0.0:Control.DeepSeq.NFData{tc rou}
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
Trac metadata
| Trac field | Value |
|---|---|
| Version | 6.12.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
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