*** shapely/setup.py	2016-06-29 11:29:49.000000000 -0400
--- b/setup.py	2016-07-09 01:51:37.759670990 -0400
***************
*** 359,364 ****
--- 359,365 ----
          construct_build_ext(existing_build_ext)
      setup(ext_modules=ext_modules, **setup_args)
  except BuildFailed as ex:
+     raise # Force python only build to fail
      BUILD_EXT_WARNING = "The C extension could not be compiled, " \
                          "speedups are not enabled."
      log.warn(ex)