ImportError: Cannot use tblib. Runtime not supported.

[crdoconnor]

WARNING: IPython GUI event loop requires ctypes, %gui will not be available
Failed to initialize cpython support: ImportError('/home/user/project/tests.hitch/virtualenv/lib/python3.4/lib-dynload/_ctypes.cpython-34m-x86_64-linux-gnu.so: undefined symbol: _PyTraceback_Add',)Traceback (most recent call last):
File "/home/user/project/tests.hitch/virtualenv/bin/hitchtest", line 11, in <module>
    sys.exit(commandline.run())
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchtest/commandline.py", line 108, in run
    cli()
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/click/core.py", line 700, in __call__
    return self.main(*args, **kwargs)
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/click/core.py", line 680, in main
    rv = self.invoke(ctx)
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/click/core.py", line 873, in invoke
    return ctx.invoke(self.callback, **ctx.params)
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/click/core.py", line 508, in invoke
    return callback(*args, **kwargs)
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchtest/commandline.py", line 80, in cli
    test_modules.append(module.Module(filename, settings_dict))
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchtest/module.py", line 70, in __init__
    Test(test_yaml, self.settings, self.filename, "{} {}".format(self.title, i))
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchtest/test.py", line 33, in __init__
    engine_module = imp.load_source("engine", module_source)
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/imp.py", line 171, in load_source
    module = methods.load()
File "<frozen importlib._bootstrap>", line 1220, in load
File "<frozen importlib._bootstrap>", line 1200, in _load_unlocked
File "<frozen importlib._bootstrap>", line 1129, in _exec
File "<frozen importlib._bootstrap>", line 1448, in exec_module
File "<frozen importlib._bootstrap>", line 321, in _call_with_frames_removed
File "/home/user/project/testsengine.py", line 5, in <module>
    import hitchpython
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchpython/__init__.py", line 1, in <module>
    from hitchpython.django_service import DjangoService
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchpython/django_service.py", line 1, in <module>
    from hitchserve import Service
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchserve/__init__.py", line 2, in <module>
    from hitchserve.service_bundle import ServiceBundle
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchserve/service_bundle.py", line 5, in <module>
    from hitchserve.test_engine import TestEngine
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchserve/test_engine.py", line 1, in <module>
    from hitchserve.service_handle import ServiceHandle
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/hitchserve/service_handle.py", line 2, in <module>
    from tblib import pickling_support
File "/home/user/project/tests.hitch/virtualenv/lib/python3.4/site-packages/tblib/__init__.py", line 11, in <module>
    raise ImportError("Cannot use tblib. Runtime not supported.")
ImportError: Cannot use tblib. Runtime not supported.

Possible cause:

Version of python3 being upgraded, invalidating the virtualenv hitch tests run in.

Current workaround:

hitch clean
hitch init