| I'm not sure why some people see this and others don't. Anyway, John | Dias has also seen it, and he and Duncan | are working on a patch for it (basically, Cabal needs to pass a "-B | <path>" flag to gcc, to tell it where its bits are).
My best guess is that it's a mingw issue, something that chanced in recent release. It seems to effect more than just GHC.
If it was just a mingw issue, you could simply go back to an old mingw (mine has gcc 3.4.2). From what I can tell (and I'm just a user) there are interactions with Vista and cygwin. Vista changed some APIs wrt earlier windows versions, which needed following, and occasionally someone changes mingw without taking those changes into account. I thought that mingw had decoupled from the cygwin version of mingw, but there is still talk about that, about not picking up the wrong versions of gcc tools (which relates to usage of -B). Anyway, you can read about it on the mingw mailing list and bug tracker. Below is an email I was about to send when Neil reported that he had got things going himself. Claus ----------------- 1. are you using - cygwin bash+mingw gcc - msys bash+mingw gcc? 2. are you using windows vista? As a point of reference, I'm using cygwin bash and build tools (with no cygwin gcc chain installed) plus mingw gcc (3.4.2) on windows xp, and ghc issues arising tend not to be in mingw or cygwin for this config. There do seem to be quite a few vista issues for mingw (and there have been similar things for cygwin), some fixed, some not, some closed with unhelpful "read the wiki". There's a bug tracker here: https://sourceforge.net/tracker/?group_id=2435&atid=102435 https://sourceforge.net/tracker/index.php?func=detail&aid=1593268&group_id=2435&atid=202435 https://sourceforge.net/tracker/index.php?func=detail&aid=1784372&group_id=2435&atid=102435 Some tickets refer to cc1, some to header files, some are rather old, suggesting that things have been fixed, but some are new? That looks rather confusing to me, as I thought that mingw and cygwin had adapted to the api changes in vista, but then I'm still using xp.