Box2D make environment error: RAND_LIMIT_swigconstant

[JKCooper2]

Installed most recent gym and when running env = gym.make('LunarLander-v0') for the Box2D environments it's displaying the error:

[2016-05-10 19:13:27,417] Making new env: LunarLander-v0
Traceback (most recent call last):
  File "/home/jesse/AI/OpenAI/openai/Environments/CartPole-v0/CartPole-v0.py", line 58, in <module>
    main()
  File "/home/jesse/AI/OpenAI/openai/Environments/CartPole-v0/CartPole-v0.py", line 13, in main
    env = gym.make('LunarLander-v0')
  File "/home/jesse/AI/OpenAI/gym/gym/envs/registration.py", line 79, in make
    return spec.make()
  File "/home/jesse/AI/OpenAI/gym/gym/envs/registration.py", line 54, in make
    cls = load(self._entry_point)
  File "/home/jesse/AI/OpenAI/gym/gym/envs/registration.py", line 13, in load
    result = entry_point.load(False)
  File "/home/jesse/anaconda3/envs/openai/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2229, in load
    return self.resolve()
  File "/home/jesse/anaconda3/envs/openai/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2235, in resolve
    module = __import__(self.module_name, fromlist=['__name__'], level=0)
  File "/home/jesse/AI/OpenAI/gym/gym/envs/box2d/__init__.py", line 1, in <module>
    from gym.envs.box2d.lunar_lander import LunarLander
  File "/home/jesse/AI/OpenAI/gym/gym/envs/box2d/lunar_lander.py", line 4, in <module>
    import Box2D
  File "/home/jesse/anaconda3/envs/openai/lib/python2.7/site-packages/Box2D/__init__.py", line 20, in <module>
    from .Box2D import *
  File "/home/jesse/anaconda3/envs/openai/lib/python2.7/site-packages/Box2D/Box2D.py", line 435, in <module>
    _Box2D.RAND_LIMIT_swigconstant(_Box2D)
AttributeError: 'module' object has no attribute 'RAND_LIMIT_swigconstant'

_Box2D is being loaded correctly as I can modify the Box2D.py file to display _Box2D.RAND_LIMIT before the _Box2D.RAND_LIMIT_swigconstant(_Box2D) call. Seems to be affecting all _swig_constant calls (commenting out the offending line then throws and error on _Box2D.b2_pi_swigconstant(_Box2D). Does another library need to be installed to get this to work?

[gdb]

Here are some instructions from @jonasschneider (I think he's adding or already added to our box2d package):

HINT: To install box2d-py, you need Swig >= 3.0.0.
On OS X, `brew upgrade && brew install swig` should get you the latest
version.
Current Ubuntu stable versions include a recent package, so `apt-get
install swig` should be enough there.
However, on the older Ubuntu 14.04 LTS, you need to install a backported version
(be careful, these commands remove any installed older versions of Swig):

    echo deb http://archive.ubuntu.com/ubuntu trusty-backports main restricted universe multiverse | sudo tee /etc/apt/sources.list.d/box2d-py-swig.list
    apt-get install -t trusty-backports swig3.0
    apt-get remove swig swig2.0
    ln -s /usr/bin/swig3.0 /usr/bin/swig

We'll make this better over time, but it'll be a non-trivial change.