Upgrading packages

From HaskellWiki

Information about adapting packages to new a version of GHC or Cabal can be found on the following pages:

Detailed information about changes in the latest GHC release can be found in the GHC User’s Guide

Most new tips for fixing build failures are tracked at https://github.com/haskell-infra/hackage-trustees/blob/master/cookbook.md

Compatibility with older GHC[edit]

To maintain compatibility with older versions of GHC, use a conditional block in the .cabal file, checking on implementation (ghc >= x.y.z). For example:

  if impl(ghc >= 6.12)
    ghc-options:     -fno-warn-unused-do-bind