Among many programmers, and/or users who manually unpack source tarball before installing, this idiom is very common: cabal configure cabal build cabal install This idiom is an urban legend, i.e., a popular error. "cabal install" re-does the "configure" and the "build" steps, among other things. That it has not caused trouble for you so far is only because: 1. "configure" has been idempotent, so far 2. the 2nd "build" has not caused duplicate work because ghc knows when not to re-compile One day, you will run into a surprise, because you will add some flags to "configure", and then... cabal configure --prefix=/nondefault --enable-shared cabal build cabal install Whee! Your laborously entered flags are lost on deaf ears. You get the default prefix, and you get the default disable-shared. Why? Because "cabal install" re-does the "configure" step, but this time, since you give no flags to "install", you give no flags to the 2nd "configure" either. If you begin with "cabal configure", the correct idiom is: cabal configure [flags] cabal build [cabal haddock, if you want] cabal copy cabal register If you find it too long, why not just begin with: cabal install [flags] [--enable-documentation, if you want]