Resolving dependencies...
Configuring mtl-2.2.1...
Configuring network-2.6.3.1...
Building mtl-2.2.1...
Building network-2.6.3.1...
Installed mtl-2.2.1
Configuring primitive-0.6.1.0...
Building primitive-0.6.1.0...
Configuring stm-2.4.4.1...
Installed primitive-0.6.1.0
Building stm-2.4.4.1...
Configuring transformers-compat-0.5.1.4...
Installed network-2.6.3.1
Building transformers-compat-0.5.1.4...
Configuring text-1.2.2.1...
Installed stm-2.4.4.1
Installed transformers-compat-0.5.1.4
Configuring vector-0.11.0.0...
Building text-1.2.2.1...
Building vector-0.11.0.0...
Configuring exceptions-0.8.3...
Installed text-1.2.2.1
Building exceptions-0.8.3...
Configuring mmorph-1.0.7...
Installed exceptions-0.8.3
Building mmorph-1.0.7...
Configuring transformers-base-0.4.4...
Installed mmorph-1.0.7
Building transformers-base-0.4.4...
Installed vector-0.11.0.0
Configuring hashable-1.2.4.0...
Configuring pipes-4.2.0...
Installed transformers-base-0.4.4
Building hashable-1.2.4.0...
Building pipes-4.2.0...
Configuring network-simple-0.4.0.5...
Failed to install pipes-4.2.0
Build log ( /home/builder/.cabal/logs/pipes-4.2.0.log ):
cabal: Entering directory '/tmp/cabal-tmp-4172/pipes-4.2.0'
Configuring pipes-4.2.0...
Building pipes-4.2.0...
Preprocessing library pipes-4.2.0...
[1 of 6] Compiling Pipes.Internal   ( src/Pipes/Internal.hs, dist/build/Pipes/Internal.o )

src/Pipes/Internal.hs:151:24: error:
    • Could not deduce (Monad m) arising from a use of ‘observe’
      from the context: Functor m
        bound by the type signature for:
                   hoist :: Functor m =>
                            (forall a1. m a1 -> n a1)
                            -> Proxy a' a b' b m b1 -> Proxy a' a b' b n b1
        at src/Pipes/Internal.hs:151:5-9
      Possible fix:
        add (Monad m) to the context of
          the type signature for:
            hoist :: Functor m =>
                     (forall a1. m a1 -> n a1)
                     -> Proxy a' a b' b m b1 -> Proxy a' a b' b n b1
    • In the first argument of ‘go’, namely ‘(observe p0)’
      In the expression: go (observe p0)
      In an equation for ‘hoist’:
          hoist nat p0
            = go (observe p0)
            where
                go p
                  = case p of {
                      Request a' fa -> Request a' (\ a -> ...)
                      Respond b fb' -> Respond b (\ b' -> ...)
                      M m -> M (nat (m >>= ...))
                      Pure r -> Pure r }

src/Pipes/Internal.hs:156:39: error:
    • Could not deduce (Monad m) arising from a use of ‘>>=’
      from the context: Functor m
        bound by the type signature for:
                   hoist :: Functor m =>
                            (forall a1. m a1 -> n a1)
                            -> Proxy a' a b' b m b1 -> Proxy a' a b' b n b1
        at src/Pipes/Internal.hs:151:5-9
      Possible fix:
        add (Monad m) to the context of
          the inferred type of
          go :: Proxy a'1 a1 b'1 b2 m r -> Proxy a'1 a1 b'1 b2 n r
          or the type signature for:
               hoist :: Functor m =>
                        (forall a1. m a1 -> n a1)
                        -> Proxy a' a b' b m b1 -> Proxy a' a b' b n b1
    • In the first argument of ‘nat’, namely
        ‘(m >>= \ p' -> return (go p'))’
      In the first argument of ‘M’, namely
        ‘(nat (m >>= \ p' -> return (go p')))’
      In the expression: M (nat (m >>= \ p' -> return (go p')))
cabal: Leaving directory '/tmp/cabal-tmp-4172/pipes-4.2.0'
Building network-simple-0.4.0.5...
Installed hashable-1.2.4.0
Configuring monad-control-1.0.1.0...
Building monad-control-1.0.1.0...
Configuring case-insensitive-1.2.0.7...
Installed network-simple-0.4.0.5
Building case-insensitive-1.2.0.7...
Configuring scientific-0.3.4.9...
Installed monad-control-1.0.1.0
Building scientific-0.3.4.9...
Installed case-insensitive-1.2.0.7
Installed scientific-0.3.4.9
Configuring attoparsec-0.13.1.0...
Building attoparsec-0.13.1.0...
Installed attoparsec-0.13.1.0
cabal: Error: some packages failed to install:
http-pony-0.1.0.0 depends on pipes-4.2.0 which failed to install.
pipes-4.2.0 failed during the building phase. The exception was:
ExitFailure 1
pipes-attoparsec-0.5.1.4 depends on pipes-4.2.0 which failed to install.
pipes-network-0.6.4.1 depends on pipes-4.2.0 which failed to install.
pipes-parse-3.0.7 depends on pipes-4.2.0 which failed to install.
pipes-safe-2.2.4 depends on pipes-4.2.0 which failed to install.