Question

I am trying to take my Haskell project and split it apart into a library and a set of executables that depend on the library. When I try to compile now I get the following error:

src/Main.hs:23:0:
    Bad interface file: /Users/<MyHomeDir>/.cabal/lib/Core-0.0.1/ghc-6.12.1/<MyModule>.hi
        mismatched interface file ways (wanted "", got "p")

I believe that the p might be the p flag related to packages for ghc. Is this correct? Do I need to add more configuration options somewhere to my cabal file to support this?

Answer 1

That’s saying it found a profiling build, but you’re building Main.hs without profiling enabled. Quick fixes:

• enable profiling in the build for Main.hs
• build and install <MyModule> with profiling enabled

Either way, that will begin with a command that resembles

$ runghc Setup.hs configure --enable-library-profiling