incorrect link paths for in mac os x after install

I've built and installed 7.4.2 fron source:

iceman:ghc-7.4.2 andy$ otool -L /usr/local/lib/ghc-7.4.2/libHSrts-ghc7.4.2.dylib/usr/local/lib/ghc-7.4.2/libHSrts-ghc7.4.2.dylib:
	/usr/local/lib/ghc-7.4.2/libHSrts-ghc7.4.2.dylib (compatibility version 0.0.0, current version 0.0.0)
	/Users/andy/src/ghc-7.4.2/libffi/build/inst/lib/libffi.5.dylib (compatibility version 6.0.0, current version 6.10.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 159.1.0)
	/opt/local/lib/gcc47/libgcc_s.1.dylib (compatibility version 1.0.0, current version 1.0.0)

Lib rts still links again the libffi in my home directory.

It should be linked against:

/usr/local/lib/ghc-7.4.2/libffi.dylib

This problem also affects the binary distribution.