Haskell ghc compiling/linking error, not creating executable. (linux)

Have you binutils-gold installed? If yes, this is the problem (since the gold linker does not support --hash-size AFAIK).

Possible solutions:

1. remove gold
2. your ld probably links to ld.gold, so change the symlink to ld.ld
3. tell the haskell compiler explicitly which linker to use with the -pgml option: ghc -pgml ld.ld tupel.hs
4. install ghc from source, since the configure script of ghc will then build ghc so that it won't use --hash-size
5. Depending on your version of ghc, you can adjust the linker settings in ghc's setting file /usr/lib/ghc-your.ghc.version/settings

Update - gold on Ubuntu 12.10 appears to move GNU ld to ld.bfd. To fix this problem I deleted the ld link as recommended and remade the link with

  ln -s ld.bfd ld

ghc compilations are now going through.

(Couldn't see how to subvert the settings file in usr/lib/ghc, as the entry is for gcc which passes through its commandline to ld, although this would have been my preferred option, in case something else needs ld to be the way it was.)

Thanks to Dominic for the pointer of where to look! It was driving me crazy...