Greetings. I haven't tested this with ghc 6.4 yet, and I don't know if this is a known problem. I noticed this while building support for cabal. I have two mutually recursive modules, prepared as described in the GHC 6.2 user's manual: A and B I create A.hi-boot in B, in import {-source-} A This works fine. But now I create C, which imports B (not A). When I compile with --make, A does not get built, and I get a link-time error. However, if C imports A directly, it builds everything just fine. I've attached a tarball with the example. Test it like this: % ghc --make C.hs Chasing modules from: C.hs Compiling B ( ./B.hs, ./B.o ) Compiling Main ( C.hs, C.o ) Linking ... ./B.o(.text+0x1b): In function `__stginit_B_': : undefined reference to `__stginit_A_' collect2: ld returned 1 exit status peace, isaac p.s. please CC me on replies; i'm not subscribed to this mailing list