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我正在嘗試構建項目Barbarosa,它需要包stream-fusion-0.1.2.5。然而cabal install
失敗,出現以下無法安裝Haskell包流融合-0.1.2.5:不明確的發生
[3 of 3] Compiling Control.Monad.Stream (Control/Monad/Stream.hs, dist/dist-sandbox-8bb5b9c9/build/Control/Monad/Stream.o)
Control/Monad/Stream.hs:136:10:
Ambiguous occurrence ‘MonadPlus’
It could refer to either ‘Control.Monad.Stream.MonadPlus’,
defined at Control/Monad/Stream.hs:124:1
or ‘GHC.Base.MonadPlus’,
imported from ‘GHC.Base’ at Control/Monad/Stream.hs:80:1-15
Control/Monad/Stream.hs:140:10:
Ambiguous occurrence ‘MonadPlus’
It could refer to either ‘Control.Monad.Stream.MonadPlus’,
defined at Control/Monad/Stream.hs:124:1
or ‘GHC.Base.MonadPlus’,
imported from ‘GHC.Base’ at Control/Monad/Stream.hs:80:1-15
我使用GHC版本7.10.2在OS X 10.11,通過哈斯克爾平臺安裝。
看來的stream-fusion
唯一的依賴是base
其版本應該是很好,所以我不知道什麼是錯在這裏。
該軟件包的'Control.Monad.Stream'模塊定義了自己的'MonadPlus'類型類。我認爲這個軟件包簡直太爛了。 – Cactus
我懷疑'GHC.Base'沒有用來導出'MonadPlus',但是由於7.10的改變而改變了。 –