Duncan Coutts
I think the problem here is search paths. Try adding . to the Hs-Source-Dirs, or alternatively moving everything into the root dir rather than under exec.
If you add . to the Hs-Source-Dirs, you build module A twice, once for the library, and once for the building of b. Notice b is not linked with the library. $ runhaskell Setup.hs build Preprocessing library a-1.0... Preprocessing executables for a-1.0... Building a-1.0... [1 of 1] Compiling A ( A.hs, dist/build/A.o ) /usr/bin/ar: creating dist/build/libHSa-1.0.a [1 of 2] Compiling A ( A.hs, dist/build/b/b-tmp/A.o ) [2 of 2] Compiling Main ( exec/Main.hs, dist/build/b/b-tmp/Main.o ) Linking dist/build/b/b ... $
This smells like a bug in cabal to me.
Time for me to submit a bug report? John