Currently HaRe (on hackage) supports GHC 7.10 and 8.0 There is a new version ready to roll, with GHC 8.2 and 8.4 support. But due to the complexities of the build environment (details here[1] for anyone who cares) it will not be able to support earlier GHC versions. Will this be a problem for anyone? Alan [1] https://github.com/haskell/cabal/pull/5275