
#7959: Panic on deriving nullary typeclass -------------------------------+-------------------------------------------- Reporter: monoidal | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.7 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: Compile-time crash | Blockedby: Blocking: | Related: -------------------------------+-------------------------------------------- {{{ {-# LANGUAGE NullaryTypeClasses #-} class C }}} Both `data A deriving C` and `deriving instance C` cause panic. Patch attached. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7959 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler