Resolving dependencies...
Configuring mtl-2.2.1...
Configuring text-1.2.2.1...
Building mtl-2.2.1...
Building text-1.2.2.1...
Installed mtl-2.2.1
Installed text-1.2.2.1
Configuring parsec-3.1.11...
Building parsec-3.1.11...
Installed parsec-3.1.11
Configuring scan-0.1.0.2...
Building scan-0.1.0.2...
Failed to install scan-0.1.0.2
Build log ( /home/builder/.cabal/logs/scan-0.1.0.2.log ):
cabal: Entering directory '/tmp/cabal-tmp-14686/scan-0.1.0.2'
Configuring scan-0.1.0.2...
Building scan-0.1.0.2...
Preprocessing executable 'scan' for scan-0.1.0.2...
[1 of 2] Compiling Language.Haskell.Scanner ( src/Language/Haskell/Scanner.hs, dist/build/scan/scan-tmp/Language/Haskell/Scanner.o )
[2 of 2] Compiling Main             ( src/scan.hs, dist/build/scan/scan-tmp/Main.o )

src/scan.hs:1:1: error:
    The IO action ‘main’ is not exported by module ‘Main’
cabal: Leaving directory '/tmp/cabal-tmp-14686/scan-0.1.0.2'
cabal: Error: some packages failed to install:
scan-0.1.0.2 failed during the building phase. The exception was:
ExitFailure 1