Resolving dependencies... Configuring concatenative-1.0.1... Configuring mtl-2.2.1... Building concatenative-1.0.1... Building mtl-2.2.1... Installed concatenative-1.0.1 Configuring text-1.2.2.1... Building text-1.2.2.1... Installed mtl-2.2.1 Configuring regex-base-0.93.2... Building regex-base-0.93.2... Installed regex-base-0.93.2 Configuring regex-posix-0.95.2... Building regex-posix-0.95.2... Installed regex-posix-0.95.2 Installed text-1.2.2.1 Configuring parsec-3.1.11... Building parsec-3.1.11... Installed parsec-3.1.11 Configuring indents-0.3.3... Building indents-0.3.3... Installed indents-0.3.3 Configuring herbalizer-0.4.9... Building herbalizer-0.4.9... Failed to install herbalizer-0.4.9 Build log ( /home/builder/.cabal/logs/herbalizer-0.4.9.log ): cabal: Entering directory '/tmp/cabal-tmp-10876/herbalizer-0.4.9' Configuring herbalizer-0.4.9... Building herbalizer-0.4.9... Preprocessing executable 'herbalizer' for herbalizer-0.4.9... [1 of 1] Compiling Main ( src/Main.hs, dist/build/herbalizer/herbalizer-tmp/Main.o ) src/Main.hs:152:5: error: • Non type-variable argument in the constraint: Stream s m Char (Use FlexibleContexts to permit this) • When checking the inferred type betweenStuff :: forall (m :: * -> *) u s. Stream s m Char => Char -> Char -> ParsecT s u m [Char] In an equation for ‘rubyValue’: rubyValue = do { xs <- many (noneOf "},([ \t") <* spaces; rest <- ((lookAhead (oneOf ",}") >> return "")) <|> (betweenStuff '(' ')') <|> (betweenStuff '[' ']'); return $ "<%= " ++ xs ++ rest ++ " %>" } where betweenStuff x y = do { xs' <- between (char x) (char y) (many $ noneOf ...); .... } src/Main.hs:187:1: error: • Non type-variable argument in the constraint: Stream s (State SourcePos) z (Use FlexibleContexts to permit this) • When checking the inferred type filterBlock :: forall a u s z. Stream s (State SourcePos) z => ParsecT s u (State SourcePos) a -> IndentParser s u [a] cabal: Leaving directory '/tmp/cabal-tmp-10876/herbalizer-0.4.9' cabal: Error: some packages failed to install: herbalizer-0.4.9 failed during the building phase. The exception was: ExitFailure 1