Resolving dependencies... Downloading yajl-0.3.2... Configuring yajl-0.3.2... cabal: Missing dependency on a foreign library: * Missing C library: yajl This problem can usually be solved by installing the system package that provides this library (you may need the "-dev" version). If the library is already installed but in a non-standard location then you can use the flags --extra-include-dirs= and --extra-lib-dirs= to specify where it is. Failed to install yajl-0.3.2 cabal: Error: some packages failed to install: yajl-0.3.2 failed during the configure step. The exception was: ExitFailure 1