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Bug 646662 - [haskell overlay] dev-haskell/transformers-0.4.3.0 - Control/Monad/Trans/Error.hs:69:10: error: Duplicate instance declarations: instance MonadPlus IO
Summary: [haskell overlay] dev-haskell/transformers-0.4.3.0 - Control/Monad/Trans/Erro...
Status: CONFIRMED
Alias: None
Product: Gentoo Linux
Classification: Unclassified
Component: Current packages (show other bugs)
Hardware: All Linux
: Normal normal (vote)
Assignee: Gentoo's Haskell Language team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2018-02-05 13:18 UTC by Alessandro Di Federico
Modified: 2018-05-12 21:55 UTC (History)
1 user (show)

See Also:
Package list:
Runtime testing required: ---


Attachments
build.log (transformers.log,3.21 KB, application/gzip)
2018-02-05 13:18 UTC, Alessandro Di Federico
Details

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Description Alessandro Di Federico 2018-02-05 13:18:15 UTC
Created attachment 517868 [details]
build.log

dev-haskell/transformers-0.4.3.0 fails to build with dev-lang/ghc-8.0.2 with the attached error message.

Control/Monad/Trans/Error.hs:69:10: error:
    Duplicate instance declarations:
      instance MonadPlus IO
        -- Defined at Control/Monad/Trans/Error.hs:69:10
      instance MonadPlus IO -- Defined in ‘GHC.Base’

Control/Monad/Trans/Error.hs:73:10: error:
    Duplicate instance declarations:
      instance Alternative IO
        -- Defined at Control/Monad/Trans/Error.hs:73:10
      instance Alternative IO -- Defined in ‘GHC.Base’
Comment 1 Sergei Trofimovich (RETIRED) gentoo-dev 2018-05-12 21:55:02 UTC
ghc-8.0.2 comes with transformers-0.5.2.0. Your system should use those. Do you know what holds old transformers back for you?