-fext-core -fno-core behaves funny
Suppose I have a module Main.hs which I have already compiled, which means I already have Main.hi. Now I compile it again with the flags -fext-core and -fno-code. What happens now is that ghc says: compilation IS NOT required and generates an a.out (!) but not a Main.hcr. Now this really surprised me. I expected that no a.out should be generated (since I give the -fno-code flag) but that Main.hcr still should be generated.