build against libstdc++-4.8-dev

.travis.yml

@@ -35,7 +35,7 @@ matrix:
       addons:
         apt:
           sources: [ 'ubuntu-toolchain-r-test']
-          packages: [ 'libstdc++-4.9-dev', 'xutils-dev']
+          packages: [ 'libstdc++-4.8-dev', 'xutils-dev']
     - os: linux
       sudo: false
       compiler: ": clang-coverage"
@@ -43,7 +43,7 @@ matrix:
       addons:
         apt:
           sources: [ 'ubuntu-toolchain-r-test']
-          packages: ['libstdc++-4.9-dev', 'xutils-dev' ]
+          packages: ['libstdc++-4.8-dev', 'xutils-dev' ]
     - os: osx
       compiler: ": clang-osx"
       # https://docs.travis-ci.com/user/languages/objective-c/#Supported-OS-X-iOS-SDK-versions
@@ -102,6 +102,7 @@ script:
  - DURATION=2400
  - scripts/travis-command-wrapper.py -s "date" -i 120 --deadline=$(( $(date +%s) + ${DURATION} )) make
  - RESULT=0
+ - nm src/libmapnik.* | grep throw_out_of_range
  - make test || RESULT=$?
  # we allow visual failures with g++ for now: https://github.com/mapnik/mapnik/issues/3567
  - if [[ ${RESULT} != 0 ]] && [[ ${CXX} =~ 'clang++' ]]; then false; fi;