#12525: Internal identifiers creeping into :show bindings -------------------------------------+------------------------------------- Reporter: mniip | Owner: Type: bug | Status: new Priority: low | Milestone: Component: GHCi | Version: 8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Ugh. The underlying problem is that the GHCi `InteractiveContext` doesn't make a proper distinction between * things lexically in scope (`ic_rn_gbl_env :: GlobalRdrEnv`) * things that the typechecker might need (`ic_tythings :: [TyThing]`) Instead the former is (more or less, I think) generated from the latter. But that's problematic for these internal identifiers. We came across this before: #11051. Easiest fix is to use the same solution for `showBindings`, namely to use `isDerivedOccName` to filter out the internal ones. See `Note [What to show to users]` in `InteractiveEval.hs`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12525#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler