[Haskell-cafe] Tell cabal-install to generate only shared libraries

Hello, When I tell cabal-install to build shared libraries (with "Shared: True" in .cabal/config), it doubles the libraries installation time since it compiles them twice, since it seems that is what GHC's flag "-shared" does. Is there a way to generate only the .so and not the the .a libs? Furthermore, I have the impression that the executables compiled by cabal-install are always linked statically... Can I tell cabal-install to activate the GHC's flag "-dynamic" for executables? Thanks.