[Haskell-beginners] Developing dependant libraries simultaneously

[John Smith]

I am working on libraries A, B, and C simultaneously. B and C both depend on A. Whenever A changes, I have to rebuild an 
reinstall it for the changes to be picked up by B and C.

Is there any way to tell cabal or GHC that B and C should import A, and check for changes when building? I'm using 
EclipseFP, but adding a project-reference does not appear to have any effect.