.travis.yml

sudo: false
dist: trusty
language: c

matrix:
  include:
    - env: CABALVER=2.2 GHCVER=8.4.1
      addons: { 
        apt: {
          packages: [cabal-install-2.2,ghc-8.4.1,libsdl2-dev,happy-1.19.5,alex-3.1.7,
                     libgirepository1.0-dev,libgtk-3-dev,libcairo2-dev,libcairo-gobject2], 
          sources: [hvr-ghc]
        }
      }
    - env: CABALVER=2.0 GHCVER=8.0.2
      addons: { 
         apt: {
           packages: [cabal-install-2.0,ghc-8.0.2,libsdl2-dev,happy-1.19.5,alex-3.1.7,
                      libgirepository1.0-dev,libgtk-3-dev,libcairo2-dev,libcairo-gobject2], 
           sources: [hvr-ghc]
         }
       } 

before_install:
 - mkdir -p ~/.local/bin
 - export PATH=$HOME/.cabal/bin:/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:/opt/alex/3.1.7/bin:/opt/happy/1.19.5/bin:$HOME/.local/bin:$PATH

install:
 - cabal --version
 - echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
 - travis_retry cabal update

# Here starts the actual work to be performed for the package under test; any command which exits with a non-zero exit code causes the build to fail.
script:
 - travis_retry cabal update 
 - travis_retry cabal new-build all

cache:
 directories:
 - $HOME/.cabal/packages
 - $HOME/.cabal/store
 - $HOME/.cabal/bin