#13458: Panic with unsafeCoerce and -dcore-lint -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler (Type | Version: 8.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rwbarton): If you change the type signature to `unsafeCoerce' :: Int# -> Int#` then the generated core is {{{ unsafeCoerce' = (id @ Any) `cast` (UnsafeCo representational Any Int# -> UnsafeCo representational Any Int# :: ((Any -> Any) :: *) ~R# ((Int# -> Int#) :: *)) }}} Optimizing the coercion like this seems dubious when the new coercions are ill-kinded. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13458#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler