haskell/cabal — pull request #1390 by 23Skidoo (2013-07-17 17:13:16+00:00)
Title: Pass '--libdir' etc to 'setup configure' when installing.

Otherwise libs with 'build-type: Custom' get installed under
'$prefix/lib/$pkgname' instead of '$prefix/lib/$arch-$compiler-$os/$pkgname'.