#13622: Regression: can't export constructor when conflicting, qualified constructor is also in scope -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.2.1-rc2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I ran into this regression when trying to compile the `ersatz` library with GHC 8.2.1-rc1. Here is a minimized example: {{{#!hs module Bug (Bits(Bits)) where import qualified Data.Bits as Bits newtype Bits = Bits Int }}} Compiling this with GHC 8.0.2 works fine, but with 8.2.1-rc1, you get this error: {{{ l$ /opt/ghc/8.2.1/bin/ghci Bug.hs GHCi, version 8.2.0.20170422: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Bug ( Bug.hs, interpreted ) Bug.hs:1:13: error: • Ambiguous occurrence ‘Bits’ It could refer to either ‘Bits.Bits’, imported qualified from ‘Data.Bits’ at Bug.hs:3:1-34 or ‘Bits’, defined at Bug.hs:5:1 • In the export: Bits(Bits) | 1 | module Bug (Bits(Bits)) where | ^^^^^^^^^^ }}} Despite the fact that `Bits` isn't actually ambiguous, since the `Bits` from `Data.Bits` is qualified. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13622 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler