#14777: panic when using a function defined in terms of `error` -------------------------------------+------------------------------------- Reporter: zilinc | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.2 Resolution: | Keywords: Operating System: Linux | 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 tdammers): Replying to [comment:16 dfeuer]:
About all I can see about what's gone wrong is that something seems to be treating a type variable as though it were a term variable. That is, if I understand the `Var` type properly.
I've been suspecting some sort of type/term confusion myself - neither `error` nor `undefined` should, conceptually speaking, throw the type checker off guard, and they shouldn't produce different behavior as far as the types are concerned (both `error "Something"` and `undefined` are `forall a. a`, essentially), yet swapping one for the other seems to toggle the panic. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14777#comment:18 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler