Summary

GHC panics with:

ghc: panic! (the 'impossible' happened)
  (GHC version 8.6.3 for x86_64-apple-darwin):
	filterImports/combine
  (field, field, Nothing)
  ($sel:field:R, R{R, R; field}, Nothing)
  Call stack:
      CallStack (from HasCallStack):
        callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable
        pprPanic, called at compiler/rename/RnNames.hs:901:23 in ghc:RnNames

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Steps to reproduce

A.hs:

module Main where

import B hiding (field)

main = print "ok"

B.hs:

{-# LANGUAGE DuplicateRecordFields #-}

module B
  ( R(..)
  , module C
  ) where

import C

data R = R { field :: Int}

C.hs:

module C where
field = (++ "foo")

Expected behavior

compile time error instead of ghc panic

Environment

• GHC version used: 8.6.3

Optional:

• Operating System: OS X Sierra
• System Architecture: x86_64