the bug was in SWIG pre 2.0.8. Update travis to use ubuntu raring, which has this.

.travis.yml

@@ -23,6 +23,7 @@ matrix:
       perl: 5.18
       env: BINDINGS=perl CC=clang
 before_install:
+  - sudo add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu raring main universe"
   - sudo apt-get update -qq
   - if [ "$BINDINGS" == "python" ]; then sudo apt-get install -qq swig python-dev; fi
   - if [ "$BINDINGS" == "perl" ]; then sudo apt-get install -qq swig; fi