Travis update

.travis.yml

@@ -1,3 +1,10 @@
+# This is the complex Travis configuration, which is intended for use
+# on open source libraries which need compatibility across multiple GHC
+# versions, must work with cabal-install, and should be
+# cross-platform. For more information and other options, see:
+#
+# https://docs.haskellstack.org/en/stable/travis_ci/
+#
 # Copy these contents into the root directory of your Github project in a file
 # named .travis.yml
 
@@ -60,35 +67,35 @@ matrix:
   # variable, such as using --stack-yaml to point to a different file.
   - env: BUILD=stack ARGS=""
     compiler: ": #stack default"
-    addons: {apt: {packages: [ghc-7.10.3], sources: [hvr-ghc]}}
+    addons: {apt: {packages: [libgmp-dev]}}
 
   - env: BUILD=stack ARGS="--resolver lts-2"
     compiler: ": #stack 7.8.4"
-    addons: {apt: {packages: [ghc-7.8.4], sources: [hvr-ghc]}}
+    addons: {apt: {packages: [libgmp-dev]}}
 
   - env: BUILD=stack ARGS="--resolver lts-3"
     compiler: ": #stack 7.10.2"
-    addons: {apt: {packages: [ghc-7.10.2], sources: [hvr-ghc]}}
+    addons: {apt: {packages: [libgmp-dev]}}
 
   - env: BUILD=stack ARGS="--resolver lts-6"
     compiler: ": #stack 7.10.3"
-    addons: {apt: {packages: [ghc-7.10.3], sources: [hvr-ghc]}}
+    addons: {apt: {packages: [libgmp-dev]}}
 
   - env: BUILD=stack ARGS="--resolver lts-7"
     compiler: ": #stack 8.0.1"
-    addons: {apt: {packages: [ghc-8.0.1], sources: [hvr-ghc]}}
+    addons: {apt: {packages: [libgmp-dev]}}
 
   # Nightly builds are allowed to fail
   - env: BUILD=stack ARGS="--resolver nightly"
     compiler: ": #stack nightly"
-    addons: {apt: {packages: [libgmp,libgmp-dev]}}
+    addons: {apt: {packages: [libgmp-dev]}}
 
   # Build on OS X in addition to Linux
   - env: BUILD=stack ARGS=""
     compiler: ": #stack default osx"
     os: osx
 
-  # Doesn't include hfsevents
+  # Travis includes an OS X which is incompatible with GHC 7.8.4
   #- env: BUILD=stack ARGS="--resolver lts-2"
   #  compiler: ": #stack 7.8.4 osx"
   #  os: osx
@@ -142,9 +149,6 @@ before_install:
     echo 'jobs: $ncpus' >> $HOME/.cabal/config
   fi
 
-# Get the list of packages from the stack.yaml file
-- PACKAGES=$(stack --install-ghc query locals | grep '^ *path' | sed 's@^ *path:@@')
-
 install:
 - echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
 - if [ -f configure.ac ]; then autoreconf -i; fi
@@ -157,6 +161,10 @@ install:
     cabal)
       cabal --version
       travis_retry cabal update
+
+      # Get the list of packages from the stack.yaml file
+      PACKAGES=$(stack --install-ghc query locals | grep '^ *path' | sed 's@^ *path:@@')
+
       cabal install --only-dependencies --enable-tests --enable-benchmarks --force-reinstalls --ghc-options=-O0 --reorder-goals --max-backjumps=-1 $CABALARGS $PACKAGES
       ;;
   esac