Resolving dependencies...
Configuring hvect-0.3.1.0...
Configuring mtl-2.2.1...
Building mtl-2.2.1...
Building hvect-0.3.1.0...
Installed hvect-0.3.1.0
Configuring primitive-0.6.1.0...
Building primitive-0.6.1.0...
Configuring safe-0.3.10...
Installed mtl-2.2.1
Building safe-0.3.10...
Configuring text-1.2.2.1...
Installed primitive-0.6.1.0
Installed safe-0.3.10
Configuring regex-base-0.93.2...
Building text-1.2.2.1...
Building regex-base-0.93.2...
Configuring vector-0.11.0.0...
Installed regex-base-0.93.2
Building vector-0.11.0.0...
Installed text-1.2.2.1
Configuring regex-posix-0.95.2...
Building regex-posix-0.95.2...
Installed regex-posix-0.95.2
Configuring hashable-1.2.4.0...
Building hashable-1.2.4.0...
Configuring path-pieces-0.2.1...
Installed hashable-1.2.4.0
Building path-pieces-0.2.1...
Configuring regex-compat-0.95.1...
Installed path-pieces-0.2.1
Building regex-compat-0.95.1...
Configuring unordered-containers-0.2.7.1...
Installed vector-0.11.0.0
Building unordered-containers-0.2.7.1...
Installed regex-compat-0.95.1
Installed unordered-containers-0.2.7.1
Configuring graph-core-0.3.0.0...
Building graph-core-0.3.0.0...
Installed graph-core-0.3.0.0
Configuring reroute-0.3.0.1...
Building reroute-0.3.0.1...
Failed to install reroute-0.3.0.1
Build log ( /home/builder/.cabal/logs/reroute-0.3.0.1.log ):
cabal: Entering directory '/tmp/cabal-tmp-26883/reroute-0.3.0.1'
Configuring reroute-0.3.0.1...
Building reroute-0.3.0.1...
Preprocessing library reroute-0.3.0.1...
[1 of 4] Compiling Web.Routing.AbstractRouter ( src/Web/Routing/AbstractRouter.hs, dist/build/Web/Routing/AbstractRouter.o )

src/Web/Routing/AbstractRouter.hs:7:1: warning: [-Wunused-imports]
    The import of ‘Control.Applicative’ is redundant
      except perhaps to import instances from ‘Control.Applicative’
    To import instances alone, use: import Control.Applicative()
[2 of 4] Compiling Web.Routing.TextRouting ( src/Web/Routing/TextRouting.hs, dist/build/Web/Routing/TextRouting.o )
[3 of 4] Compiling Data.PolyMap     ( src/Data/PolyMap.hs, dist/build/Data/PolyMap.o )
[4 of 4] Compiling Web.Routing.SafeRouting ( src/Web/Routing/SafeRouting.hs, dist/build/Web/Routing/SafeRouting.o )

src/Web/Routing/SafeRouting.hs:56:28: error:
    Ambiguous occurrence ‘length’
    It could refer to either ‘Prelude.length’,
                             imported from ‘Prelude’ at src/Web/Routing/SafeRouting.hs:8:8-30
                             (and originally defined in ‘Data.Foldable’)
                          or ‘HV.length’,
                             imported from ‘Data.HVect’ at src/Web/Routing/SafeRouting.hs:11:1-31
cabal: Leaving directory '/tmp/cabal-tmp-26883/reroute-0.3.0.1'
cabal: Error: some packages failed to install:
reroute-0.3.0.1 failed during the building phase. The exception was:
ExitFailure 1