I'm happy to report that after about six months, enough upper bounds have been corrected on Hackage that a Stackage build with GHC 7.8 can now proceed. I've run a build with 7.8.0rc2, and have uploaded the build.log[1] and the complete cabal output for each package[2]. The good news is that most packages are building correctly, though there is still at least one package deep in the dependency tree which does not build (pcre-light). Here's a list of packages which failed to build, ignoring those which couldn't be built due to broken dependencies: * fpco-api (yes, I'm working on it) * gitlib * groundhog * monad-peel * parsestar * pcre-light * recursion-schemes * statistics * syb-extras * thyme * uniqueid [1] http://download.fpcomplete.com/ghc-7.8-builds/2014-04-09/build.log [2] http://download.fpcomplete.com/ghc-7.8-builds/2014-04-09/logs.zip