Haddock documentation not building properly

[rrnewton]

I'm having a variety of different problems trying to build
documentation for this package. If I do "runhaskell Setup.hs haddock"
I get the following:

 GHCi runtime linker: fatal error: I found a duplicate definition for symbol
__hscore_S_IFDIR
 whilst processing object file
/home/newton/.cabal/lib/directory-1.0.1.2/ghc-7.0.1/HSdirectory-1.0.1.2.o
 This could be caused by:
* Loading two different object files which export the same symbol
* Specifying the same object file twice on the GHCi command line
* An incorrect `package.conf' entry, causing some object to be
  loaded twice.
 GHCi cannot safely continue in this situation.  Exiting now.  Sorry.

If I try "cabal haddock" it fails silently with error code 127.

But if I run "haddock" by hand on the .hs files it seems to work ok.

At one point I thought I was dealing with this problem:
http://hackage.haskell.org/trac/hackage/ticket/656

In particular I believe I ran into this error:
cabal: Can't find transitive deps for haddock

[rrnewton]

The error code 127 was a separate cabal-install bug.
The "cabal haddock" option above DOES result in the transitive deps error.