The ExternalProcess method in the environment file is not closing the multiprocessing right. On line 667 of envrionments.py, you need to create two class variables instead of one self._conn, self._oconn = multiprocessing.Pipe().
By creating two class variables you close the other part of the pipe.
The ExternalProcess method in the environment file is not closing the multiprocessing right. On line 667 of envrionments.py, you need to create two class variables instead of one self._conn, self._oconn = multiprocessing.Pipe().
By creating two class variables you close the other part of the pipe.
see: https://stackoverflow.com/questions/8463008/multiprocessing-pipe-vs-queue
I can create a pull request if you want.