The reason that this worries me is that Cygwin "ld" links with libraries from the Cygwin "lib" directory rather than the Mingw equivalent, regardless of which "gcc" was used to compile the object files.

We only use ld directly when building the GHCi libraries (HSbase.o etc.), and this doesn't use any external libraries, so I think we're ok here. Normal linking of Haskell programs is done using gcc, so we'll get the right version of ld there. Cheers, Simon