trying to fix travis OS X

try catting config.log

.travis.yml

@@ -5,6 +5,7 @@ before_script:
     --disable-dependency-tracking
     --with-jpeg-includes=$JPEG/include
     --with-jpeg-libraries=$JPEG/lib
+  - cat config.log
   - make -j$JOBS -s V=0
 script:
   - make -Ctest -j$JOBS -s V=0 VERBOSE=1 check