Panic when exporting duplicate record fields from separate modules
A.hs
{-# LANGUAGE DuplicateRecordFields #-}
module A where
data R = R {unR :: Int}
B.hs
{-# LANGUAGE DuplicateRecordFields #-}
module B where
data R = R {unR :: Int}
C.hs
{-# LANGUAGE DuplicateRecordFields #-}
module C (module A, module B) where
import A
import B
Output of ghc C.hs
:
C.hs:3:21: error:ghc-stage2: panic! (the 'impossible' happened)
(GHC version 8.5.20180224 for x86_64-unknown-linux):
exportClashErr
$sel:unR:R
Call stack:
CallStack (from HasCallStack):
callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in ghc:Outputable
pprPanic, called at compiler/typecheck/TcRnExports.hs:740:22 in ghc:TcRnExports