Ah, I see GHC bug #5982, which smells awfully similar.
The bug suggests a fix along the lines of:
install_name_tool /usr/local/lib/ghc-7.4.1/libHSrts-ghc7.4.1.dylib -change
/Users/ian/zz64/ghc-7.4.1/libffi/build/inst/lib/libffi.5.dylib
/usr/local/lib/ghc-7.4.1/libffi.dylib
Presumably this is still an issue in the 7.4.2 build I have installed from Haskell Platform.
Unfortunately, it looks like my cabal build failure occurs in a temporary and very short-lived directory. So presumably the dodgy FFI gets copied into there from elsewhere. I wonder if I can find the source...
On 2013-04-07, at 8:39 PM, Luke Evans
My cabal-fu is extremely weak, so I'll plug on and see if I can figure out how cabal's analysis/build might be going wrong here. I'd be very grateful for any clues though!
-- Luke