[Haskell-cafe] why can it never go smoothly, language-c-0.4.7 edition

Hi, setup-Simple-Cabal-1.22.0.0-x86_64-linux-ghc-7.8.4: The program 'happy' is required but it could not be found. so i installed happy. then it wanted alex. which i was also able to install. and then language-c-0.4.7 successfully installed. I have seen this sort of thing many times across all sorts of different packages. So my question is : are these dependency bugs that should be reported to the package maintainer ? or is that certain packages can't be built as a dependency target for some reason ? Thanks, Brian