Not handling the failure of python setup egg_info

[mkouhei]

[2015-05-29 12:56:49,760: INFO/Worker-4] Traceback (most recent call last):
  File "<string>", line 20, in <module>
  File "/tmp/tmpvkdyrm59-py_deps/swiftype/setup.py", line 6, in <module>
    execfile(os.path.join('swiftype', 'version.py'))
NameError: name 'execfile' is not defined
(snip)
  File "/path/to/venv/lib/python3.4/site-packages/py_deps-0.4.1-py3.4.egg/py_deps/deps.py", line 118, in __init__
  File "/path/to/venv/lib/python3.4/site-packages/py_deps-0.4.1-py3.4.egg/py_deps/deps.py", line 181, in trace_chain
  File "/path/to/venv/lib/python3.4/site-packages/py_deps-0.4.1-py3.4.egg/py_deps/deps.py", line 169, in _list_requires
  File "/path/to/venv/lib/python3.4/site-packages/py_deps-0.4.1-py3.4.egg/py_deps/deps.py", line 160, in _download
  File "/path/to/venv/lib/python3.4/site-packages/pip/req/req_set.py", line 317, in prepare_files
    functools.partial(self._prepare_file, finder))
  File "/path/to/venv/lib/python3.4/site-packages/pip/req/req_set.py", line 304, in _walk_req_to_install
    more_reqs = handler(req_to_install)
  File "/path/to/venv/lib/python3.4/site-packages/pip/req/req_set.py", line 483, in _prepare_file
    abstract_dist.prep_for_dist()
  File "/path/to/venv/lib/python3.4/site-packages/pip/req/req_set.py", line 123, in prep_for_dist
    self.req_to_install.run_egg_info()
  File "/path/to/venv/lib/python3.4/site-packages/pip/req/req_install.py", line 402, in run_egg_info
    command_desc='python setup.py egg_info')
  File "/path/to/venv/lib/python3.4/site-packages/pip/utils/__init__.py", line 732, in call_subprocess
    % (command_desc, proc.returncode, cwd))
pip.exceptions.InstallationError: Command "python setup.py egg_info" failed with error code 1 in /tmp/tmpvkdyrm59-py_deps/swiftype