On Wed, May 23, 2018 at 3:50 PM, Oleg Grenrus
Hi Evan,
the cure to your problem is to put source files of different components into different directories. i.e.
Yes, that's exactly it! Thanks for the explanation.
Even Cabal tells GHC that "Foo.Public" is the only module it need to compile, GHC "discovers" ./Foo/Internal.hs and happily uses it. There are other similar interactions because of that implicitness, I'd advice to avoid having current directory "." (the default) in the hs-source-dirs.
Indeed, though it's an awkward and surprising limitation, to me at least. I would think ghc would be looking for dist/build/library/Foo/Internal.hi, and not find it. I assume it has to do with ghc --make is sort of a build system, and cabal is sort of a build system, and they sort of cooperate with each other :)