Newer alex (and happy) in CI meta

.travis.yml

@@ -112,7 +112,6 @@ before_install:
  - export PATH=$HOME/.cabal/bin:$PATH
  - export PATH=$HOME/.local/bin:$PATH
  - export PATH=/opt/cabal/2.4/bin:$PATH
- - export PATH=/opt/alex/3.1.7/bin:$PATH
  - if [ "$USE_GOLD" = "YES" ]; then sudo update-alternatives --install "/usr/bin/ld" "ld" "/usr/bin/ld.gold" 20; fi
  - if [ "$USE_GOLD" = "YES" ]; then sudo update-alternatives --install "/usr/bin/ld" "ld" "/usr/bin/ld.bfd" 10; fi
  - ld -v

travis-install.sh

@@ -13,9 +13,16 @@ if [ -z ${STACK_CONFIG+x} ]; then
     if [ "$TRAVIS_OS_NAME" = "linux" ]; then
         travis_retry sudo add-apt-repository -y ppa:hvr/ghc
         travis_retry sudo apt-get update
-        travis_retry sudo apt-get install --force-yes cabal-install-2.4 happy-1.19.5 alex-3.1.7 ghc-$GHCVER-prof ghc-$GHCVER-dyn
+        travis_retry sudo apt-get install --force-yes cabal-install-2.4 ghc-$GHCVER-prof ghc-$GHCVER-dyn
         if [ "x$TEST_OTHER_VERSIONS" = "xYES" ]; then travis_retry sudo apt-get install --force-yes ghc-7.0.4-prof ghc-7.0.4-dyn ghc-7.2.2-prof ghc-7.2.2-dyn ghc-head-prof ghc-head-dyn; fi
 
+        if [ "$SCRIPT" = "meta" ]; then
+            # change to /tmp so cabal.project doesn't affect new-install
+            cabal update
+            (cd /tmp && cabal new-install alex --constraint='alex ^>= 3.2.4')
+            (cd /tmp && cabal new-install happy --constraint='happy ^>= 1.19.9')
+        fi
+
     elif [ "$TRAVIS_OS_NAME" = "osx" ]; then
 
         case $GHCVER in