install targets on package building infrastructure

While working with Jens Petersen to improve the redhat packages for greencard, we came across a problem in the standard install targets in makefiles. Normally, we want 'make install' to: build the library install the library in /usr/lib/whatever (or similar place) invoke ghc-pkg to tell ghc about the package When building a package binary though, we only want to do the first two steps and only perform the third step on the users machine. What's the preferred way of doing this? (I figure this has already been solved for ghc and for some non-haskell packages) -- Alastair