The arithmoi package[1] does not build on GHC 7.8.1, and the maintainer does not appear to be reachable. diagram-contrib[2] depends on arithmoi, which is why I and others have been working on this. Brent reported the build failure on 2013-12-23[3]. Carter Schonwald and I wrote a patch[4] mid-February. After Austin Seipp provided ghc-prim-compat[5], I wrote an new patch[6] using that module. Daniel Fischer, the author of arithmoi, has not replied to either pull request, nor to an email I sent him a week ago today. Unless someone knows other channels by which to reach Daniel Fischer, I'd like to request that someone upload my patched version of arithmoi to Hackage. I'm not sure how this process usually works; are there other steps I should take? Thank you, Daniel Footnotes: [1] http://hackage.haskell.org/package/arithmoi [2] http://hackage.haskell.org/package/diagrams-contrib [3] https://bitbucket.org/dafis/arithmoi/issue/4/equality-primop-type-error-unde... [4] https://bitbucket.org/carter/arithmoi/ [5] https://github.com/thoughtpolice/ghc-prim-compat [6] https://bitbucket.org/bergey/arithmoi/