#4017: Unhelpful error message in GHCi -------------------------------------+------------------------------------- Reporter: simonpj | Owner: supersven Type: bug | Status: new Priority: lowest | Milestone: Component: Compiler | Version: 6.12.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by supersven): Looks like things (or symptoms) changed a bit over time - The problem seems to be the same. Starting a current version of GHC in interactive mode: {{{ [nix-shell:~/src/ghc]$ inplace/bin/ghc-stage2 --interactive GHCi, version 8.3.20170930: http://www.haskell.org/ghc/ :? for help }}} `:i GHC.Integer.Type.Integer` now responds with a "Not in scope" error. `:i Integer` still shows that `GHC.Integer.Type.Integer` is reachable: {{{ Prelude> :i GHC.Integer.Type.Integer <interactive>:1:1: error: Not in scope: ‘GHC.Integer.Type.Integer’ Prelude> :i Integer data Integer = integer-gmp-1.0.1.0:GHC.Integer.Type.S# GHC.Prim.Int# | integer-gmp-1.0.1.0:GHC.Integer.Type.Jp# {-# UNPACK #-}integer- gmp-1.0.1.0:GHC.Integer.Type.BigNat | integer-gmp-1.0.1.0:GHC.Integer.Type.Jn# {-# UNPACK #-}integer- gmp-1.0.1.0:GHC.Integer.Type.BigNat -- Defined in ‘integer-gmp-1.0.1.0:GHC.Integer.Type’ instance Eq Integer -- Defined in ‘integer-gmp-1.0.1.0:GHC.Integer.Type’ instance Ord Integer -- Defined in ‘integer-gmp-1.0.1.0:GHC.Integer.Type’ instance Show Integer -- Defined in ‘GHC.Show’ instance Read Integer -- Defined in ‘GHC.Read’ instance Enum Integer -- Defined in ‘GHC.Enum’ instance Num Integer -- Defined in ‘GHC.Num’ instance Real Integer -- Defined in ‘GHC.Real’ instance Integral Integer -- Defined in ‘GHC.Real’ }}} Setting the "integer-gmp" package doesn't change the situation: {{{ Prelude> :set -package integer-gmp package flags have changed, resetting and loading new packages... Prelude> :i Integer data Integer = integer-gmp-1.0.1.0:GHC.Integer.Type.S# GHC.Prim.Int# | integer-gmp-1.0.1.0:GHC.Integer.Type.Jp# {-# UNPACK #-}integer- gmp-1.0.1.0:GHC.Integer.Type.BigNat | integer-gmp-1.0.1.0:GHC.Integer.Type.Jn# {-# UNPACK #-}integer- gmp-1.0.1.0:GHC.Integer.Type.BigNat -- Defined in ‘integer-gmp-1.0.1.0:GHC.Integer.Type’ instance Eq Integer -- Defined in ‘integer-gmp-1.0.1.0:GHC.Integer.Type’ instance Ord Integer -- Defined in ‘integer-gmp-1.0.1.0:GHC.Integer.Type’ instance Show Integer -- Defined in ‘GHC.Show’ instance Read Integer -- Defined in ‘GHC.Read’ instance Enum Integer -- Defined in ‘GHC.Enum’ instance Num Integer -- Defined in ‘GHC.Num’ instance Real Integer -- Defined in ‘GHC.Real’ instance Integral Integer -- Defined in ‘GHC.Real’ Prelude> :i GHC.Integer.Type.Integer <interactive>:1:1: error: Not in scope: ‘GHC.Integer.Type.Integer’ }}} `GHC.Integer.Type` is still a hidden module: {{{ Prelude> import GHC.Integer.Type <no location info>: error: Could not find module ‘GHC.Integer.Type’ it is a hidden module in the package ‘integer-gmp-1.0.1.0’ }}} === Summary === The error message of `:i GHC.Integer.Type.Integer` changed to "Not in scope". But `:i Integer` still shows that the requested information would be available. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/4017#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler