Resolving dependencies...
Configuring frown-0.6...
Building frown-0.6...
Failed to install frown-0.6
Build log ( /home/builder/.cabal/logs/frown-0.6.log ):
cabal: Entering directory '/tmp/cabal-tmp-14539/frown-0.6'
Configuring frown-0.6...
Warning: 'hs-source-dirs: ./Lib' directory does not exist.
Building frown-0.6...
Preprocessing executable 'frown' for frown-0.6...
[1 of 1] Compiling Main             ( Main.lhs, dist/build/frown/frown-tmp/Main.o )

Main.lhs:39:3: error:
    Failed to load interface for ‘Lexer2’
    Perhaps you meant
      Lexer (needs flag -package-key ghc-8.0.1.20161018)
      Lexeme (needs flag -package-key ghc-8.0.1.20161018)
    Use -v to see a list of the files searched for.

Main.lhs:41:3: error:
    Failed to load interface for ‘GParser2’
    Perhaps you meant
      Parser (needs flag -package-key ghc-8.0.1.20161018)
    Use -v to see a list of the files searched for.

Main.lhs:42:3: error:
    Failed to load interface for ‘Convert’
    It is a member of the hidden package ‘ghc-8.0.1.20161018’.
    Perhaps you need to add ‘ghc’ to the build-depends in your .cabal file.
    Use -v to see a list of the files searched for.

Main.lhs:43:3: error:
    Failed to load interface for ‘LR0’
    Use -v to see a list of the files searched for.

Main.lhs:44:3: error:
    Failed to load interface for ‘Lookahead’
    Use -v to see a list of the files searched for.

Main.lhs:45:3: error:
    Failed to load interface for ‘Case’
    Use -v to see a list of the files searched for.

Main.lhs:47:3: error:
    Failed to load interface for ‘Standard’
    Use -v to see a list of the files searched for.

Main.lhs:48:3: error:
    Failed to load interface for ‘Compact’
    Use -v to see a list of the files searched for.

Main.lhs:49:3: error:
    Failed to load interface for ‘GVStack’
    Use -v to see a list of the files searched for.

Main.lhs:50:3: error:
    Failed to load interface for ‘Stackless’
    Use -v to see a list of the files searched for.

Main.lhs:51:3: error:
    Failed to load interface for ‘Base’
    Use -v to see a list of the files searched for.

Main.lhs:52:3: error:
    Failed to load interface for ‘Options’
    Use -v to see a list of the files searched for.

Main.lhs:53:3: error:
    Failed to load interface for ‘Prettier’
    Use -v to see a list of the files searched for.

Main.lhs:54:3: error:
    Failed to load interface for ‘Prettier’
    Use -v to see a list of the files searched for.

Main.lhs:55:3: error:
    Failed to load interface for ‘SearchTree’
    Use -v to see a list of the files searched for.
cabal: Leaving directory '/tmp/cabal-tmp-14539/frown-0.6'
cabal: Error: some packages failed to install:
frown-0.6 failed during the building phase. The exception was:
ExitFailure 1