travis: get python 2.6 build up for OS X

.travis.yml

@@ -37,10 +37,21 @@ compiler:
 
 # try some different compiler options
 env:
+  - TRAVIS_PYTHON=python2.6
   - TRAVIS_PYTHON=python2.7
   - TRAVIS_PYTHON=python3.5
 #  - CONFIGARGS="--enable-stack-protector"
 #  - CONFIGARGS="" WATCHMAN_VALGRIND=1
 
+# TODO: On Linux we currently use system versions of Python. That makes it
+# somewhat annoying to get third-party dependencies in, since sudo isn't
+# available. We should figure out how to solve this for real, either with
+# virtualenv or with the pyenv mechanism Hypothesis uses:
+# http://www.drmaciver.com/2015/10/a-whirlwind-tour-of-the-hypothesis-build/
+matrix:
+  exclude:
+    - os: linux
+      env: TRAVIS_PYTHON=python2.6
+
 before_script: ./travis/deps.sh
 script: ./travis/run.sh

travis/deps.sh

@@ -11,6 +11,13 @@ case `uname` in
     CFLAGS="$CFLAGS $ARCHFLAGS"
     export ARCHFLAGS CFLAGS
     case "$TRAVIS_PYTHON" in
+      python2.6)
+        pyenv install 2.6.9
+        eval "$(pyenv init -)"
+        pyenv global 2.6.9
+        # install some other required dependencies
+        pip2.6 install unittest2==1.1.0 argparse
+        ;;
       python2.7)
         pyenv install 2.7.11
         pyenv global 2.7.11