TypeError when calling marlo.make() with marlo environments

[douglasrizzo]

Hi everyone. I have installed Malmo under Manjaro Linux and Python 3.5. I was able to run Minecraft and the examples that come with Malmo. However, after installing MarLo, I tried to run examples like single_agent.py and test.py, as well as the example in the README, but every time marlo.make(...) was called I got the following error: TypeError: join() argument must be str or bytes, not 'PosixPath'.

The following code reproduces my error:

import marlo
client_pool = marlo.launch_clients(1)  # this works!

# this throws an error
join_tokens = marlo.make('MarLo-MazeRunner-v0',
                         params={ "client_pool": client_pool })

I realized marlo depends on gym, so I tried to run some gym environments and they worked. I also passed the wrong name for an environment. like MarLo-MazeRunner-v1 or senseless-test-v0 and the error was different, which makes me believe an exception only occurs when trying to load a marlo environment. Any thoughts?

[spMohanty]

@douglasrizzo : gym.make and marlo.make have different behaviours internally.
But ideally MarLo-MazeRunner-v0 should work.

Did you use the Anaconda environments provided ?

conda install -c crowdai malmo

Also can you paste the complete stacktrace ?

[douglasrizzo]

Hi @spMohanty . I am not using the Anaconda installation. I followed the steps described in the installation page telling users to set their MALMO_MINECRAFT_ROOT and MALMO_XSD_PATH environment variables accordingly.

I will try to run it with Anaconda is necessary, but I already have 3 versions of Python installed locally, so I'd like to avoid installing another one if possible.

Here is my stack trace. I used Python 3.5.5, since Malmo has no support for Python 3.6 on Linux.

$ import marlo
$ join_tokens = marlo.make('MarLo-MazeRunner-v0',
                         params={"client_pool" : marlo.launch_clients(1)})


Nothing is listening on port 57769 - will attempt to launch Minecraft from a new terminal.
Giving Minecraft some time to launch... 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ok
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-3-85914dd9009f> in <module>()
      1 join_tokens = marlo.make('MarLo-MazeRunner-v0',
----> 2                           params={"client_pool" : marlo.launch_clients(1)})
      3 
      4 

/usr/lib/python3.5/site-packages/marlo/__init__.py in make(env_key, params)
     87         env = gym.make("MarLo-RawXMLEnv-v0")
     88     else:
---> 89         env = gym.make(env_key)
     90     join_tokens = env.init(params, dry_run=True)
     91     return join_tokens

/usr/lib/python3.5/site-packages/gym/envs/registration.py in make(id)
    165 
    166 def make(id):
--> 167     return registry.make(id)
    168 
    169 def spec(id):

/usr/lib/python3.5/site-packages/gym/envs/registration.py in make(self, id)
    117         logger.info('Making new env: %s', id)
    118         spec = self.spec(id)
--> 119         env = spec.make()
    120         # We used to have people override _reset/_step rather than
    121         # reset/step. Set _gym_disable_underscore_compat = True on

/usr/lib/python3.5/site-packages/gym/envs/registration.py in make(self)
     81 
     82         elif callable(self._entry_point):
---> 83             env = self._entry_point()
     84         else:
     85             cls = load(self._entry_point)

/usr/lib/python3.5/site-packages/marlo/envs/MazeRunner/main.py in __init__(self, extra_params)
     17                 templates_folder = os.path.join(
     18                             Path(__file__).parent,
---> 19                             "templates"
     20                 )
     21         )

/usr/lib/python3.5/posixpath.py in join(a, *p)
     87                 path += sep + b
     88     except (TypeError, AttributeError, BytesWarning):
---> 89         genericpath._check_arg_types('join', a, *p)
     90         raise
     91     return path

/usr/lib/python3.5/genericpath.py in _check_arg_types(funcname, *args)
    141         else:
    142             raise TypeError('%s() argument must be str or bytes, not %r' %
--> 143                             (funcname, s.__class__.__name__)) from None
    144     if hasstr and hasbytes:
    145         raise TypeError("Can't mix strings and bytes in path components") from None

TypeError: join() argument must be str or bytes, not 'PosixPath'

[douglasrizzo]

I followed the Anaconda installation instructions now. It worked, but I had to swap lines 3 and 4 and call conda activate marlo before conda install -c crowdai malmo, probably to install the environment dependencies inside the marlo environment. Couldn't get it to work on native Python, though.

[spMohanty]

@douglasrizzo : Thanks for confirming. And yes, lines 3 and 4 should be swapped.

And yes we know about the issues with native python. We will be releasing more consistent wheels in a few days, and hopefully things will be more consistent then.

[AndKram]

Previous to Python 3.6 os.join could not accept Path objects. The "main.py" of each env could be changed to:
"""
def init(self, extra_params={}):
super(MarloEnvBuilder, self).init(
templates_folder = os.path.join(
str(Path(file).parent),
"templates"
)
)
self.params = self._default_params()