当我尝试从hackage安装Stylish-haskell软件包时，我会相对一致地得到相同的错误。 安装顺利进行，直到它安装了导管，导管无法正常安装。
错误消息的结尾：
17 warnings and 2 errors generated.
Failed to install conduit-1.0.8
cabal: Error: some packages failed to install:
conduit-1.0.8 failed during the building phase. The exception was:
ExitFailure 1
stylish-haskell-0.5.8.0 depends on conduit-1.0.8 which failed to install.
yaml-0.8.5.1 depends on conduit-1.0.8 which failed to install.
我得到的完整终端输出是：
Configuring conduit-1.0.8...
/var/folders/cn/67wph78d62qc1v_lm7z2mb980000gn/T/32054.c:1:12:
warning: control reaches end of non-void function [-Wreturn-type]
int foo() {}
^
1 warning generated.
Building conduit-1.0.8...
Preprocessing library conduit-1.0.8...
Data/Conduit/Binary.hs:165:14:
warning: missing terminating ' character [-Winvalid-pp-token]
let c' = c - S.length bs
^
Data/Conduit/Binary.hs:166:18:
warning: missing terminating ' character [-Winvalid-pp-token]
assert (c' >= 0) $
^
Data/Conduit/Binary.hs:171:34:
warning: missing terminating ' character [-Winvalid-pp-token]
pullLimited c'
^
Data/Conduit/Binary.hs:281:62:
warning: missing terminating ' character [-Winvalid-pp-token]
await >>= maybe (return $ L.fromChunks $ front []) go'
^
Data/Conduit/Binary.hs:283:11:
warning: missing terminating ' character [-Winvalid-pp-token]
go' bs =
^
Data/Conduit/Binary.hs:299:39:
warning: missing terminating ' character [-Winvalid-pp-token]
await >>= maybe (return ()) go'
^
Data/Conduit/Binary.hs:301:11:
warning: missing terminating ' character [-Winvalid-pp-token]
go' bs =
^
7 warnings generated.
Data/Conduit/Internal.hs:79:47:
warning: missing terminating ' character [-Winvalid-pp-token]
-- * /i/ is the type of values for this @Pipe@'s input stream.
^
Data/Conduit/Internal.hs:81:47:
warning: missing terminating ' character [-Winvalid-pp-token]
-- * /o/ is the type of values for this @Pipe@'s output stream.
^
Data/Conduit/Internal.hs:152:64:
warning: \u used with no following hex digits; treating as '\' followed by identifier [-Wunicode]
local f (NeedInput p c) = NeedInput (\i -> local f (p i)) (\u -> local f (c u))
^
Data/Conduit/Internal.hs:170:62:
warning: \u used with no following hex digits; treating as '\' followed by identifier [-Wunicode]
listen (NeedInput p c) = NeedInput (\i -> listen (p i)) (\u -> listen (c u))
^
Data/Conduit/Internal.hs:175:26:
warning: missing terminating ' character [-Winvalid-pp-token]
return $ do (x,w') <- listen p
^
Data/Conduit/Internal.hs:176:46:
warning: missing terminating ' character [-Winvalid-pp-token]
return (x, w `mappend` w')
^
Data/Conduit/Internal.hs:180:58:
warning: \u used with no following hex digits; treating as '\' followed by identifier [-Wunicode]
pass (NeedInput p c) = NeedInput (\i -> pass (p i)) (\u -> pass (c u))
^
Data/Conduit/Internal.hs:197:74:
warning: \u used with no following hex digits; treating as '\' followed by identifier [-Wunicode]
catchError (NeedInput p c) f = NeedInput (\i -> catchError (p i) f) (\u -> catchError (c u) f)
^
Data/Conduit/Internal.hs:306:50:
warning: missing terminating ' character [-Winvalid-pp-token]
awaitForever :: Monad m => (i -> Pipe l i o r m r') -> Pipe l i o r m r
^
Data/Conduit/Internal.hs:338:4:
error: invalid preprocessing directive
#-}
^
Data/Conduit/Internal.hs:543:13:
warning: missing terminating ' character [-Winvalid-pp-token]
pipe' <- mpipe
^
Data/Conduit/Internal.hs:544:18:
warning: missing terminating ' character [-Winvalid-pp-token]
case pipe' of
^
Data/Conduit/Internal.hs:546:29:
warning: missing terminating ' character [-Winvalid-pp-token]
_ -> return pipe'
^
Data/Conduit/Internal.hs:581:83:
warning: missing terminating ' character [-Winvalid-pp-token]
mapInput f f' (NeedInput p c) = NeedInput (mapInput f f' . p . f) (mapInput f f' . c)
^
Data/Conduit/Internal.hs:584:82:
warning: missing terminating ' character [-Winvalid-pp-token]
mapInput f f' (Leftover p i) = maybe id (flip Leftover) (f' i) $ mapInput f f' p
^
Data/Conduit/Internal.hs:605:4:
error: invalid preprocessing directive
#-}
^
Data/Conduit/Internal.hs:650:35:
warning: \u used with no following hex digits; treating as '\' followed by identifier [-Wunicode]
loop = awaitE >>= either (\u -> return (u, r)) (\_ -> loop)
^
Data/Conduit/Internal.hs:671:14:
warning: missing terminating ' character [-Winvalid-pp-token]
let final' = do
^
Data/Conduit/Internal.hs:674:58:
warning: missing terminating ' character [-Winvalid-pp-token]
return (liftIO (I.writeIORef ref False) >> src, final')
^
17 warnings and 2 errors generated.
Failed to install conduit-1.0.8
cabal: Error: some packages failed to install:
conduit-1.0.8 failed during the building phase. The exception was:
ExitFailure 1
stylish-haskell-0.5.8.0 depends on conduit-1.0.8 which failed to install.
yaml-0.8.5.1 depends on conduit-1.0.8 which failed to install.
答案 0 :(得分：8)
我不是这里的专家，但我认为这是由小牛队用标有gcc的{{1}}替换标准版clang引起的 - 半兼容包装。它不时使GHC扼流圈。您可以通过修改gcc来修复此问题，以便/usr/local/lib/ghc-7.6.3/settings条目指向有效的"C compiler command"。
例如，我从Homebrew安装了gcc 4.8，然后将设置行更改为
gcc答案 1 :(得分：5)
正如其他一些答案中所提到的，这是因为gcc被至少从Xcode 5开始被Clang取代。
GHC倾向于GCC的预处理器以支持类似#something宏的c ++，看起来Clang的行为略有不同，导致包含此类宏的haskell源的编译失败。
该修复实际上显示在Haskell平台的Mac页面上： https://www.haskell.org/platform/mac.html
它由一个简单的bash脚本组成，它充当Clang的包装器。
安装它：
通过在终端中运行以下说明来安装它：
cd ~/Downloads
chmod +x ghc-clang-wrapper
./ghc-clang-wrapper
完成后，只需重新启动cabal install命令即可正常运行。
答案 2 :(得分：1)
此问题可以通过以下解决方法修复工作。