Explicitly include homebrew paths.

.travis.yml

@@ -49,4 +49,4 @@ script:
         withgit \
           /bin/sh -c "cd /root && mkdir -p tools; wget -c http://nirbheek.in/files/binaries/ninja/linux-amd64/ninja -O /root/tools/ninja; chmod +x /root/tools/ninja; CC=$CC CXX=$CXX OBJC=$CC OBJCXX=$CXX PATH=/root/tools:$PATH MESON_FIXED_NINJA=1 ./run_tests.py -- $MESON_ARGS && chmod -R a+rwX .coverage"
     fi
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then SDKROOT=$(xcodebuild -version -sdk macosx Path) OBJC=$CC OBJCXX=$CXX PATH=$HOME/tools:$PATH MESON_FIXED_NINJA=1 ./run_tests.py --backend=ninja -- $MESON_ARGS ; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then SDKROOT=$(xcodebuild -version -sdk macosx Path) CPPFLAGS=-I/usr/local/include LDFLAGS=-L/usr/local/lib OBJC=$CC OBJCXX=$CXX PATH=$HOME/tools:$PATH MESON_FIXED_NINJA=1 ./run_tests.py --backend=ninja -- $MESON_ARGS ; fi