I recently updated my Rainbow code 1 to use multiprocessing, and it worked fine on my Macbook:

OS: macOS High Sierra 10.13.3
PyTorch version: 0.3.1 py36_cuda0.0_cudnn0.0_2
How you installed PyTorch (conda, pip, source): conda
Python version: 3.6
CUDA/cuDNN version: N/A
GPU models and configuration: N/A

However, I run into the following error (gdb backtrace 2) on my Ubuntu machine:

OS: Ubuntu 14.04.5 LTS
PyTorch version: 0.3.1 py36_cuda8.0.61_cudnn7.0.5_2
How you installed PyTorch (conda, pip, source): conda
Python version: 3.6
CUDA/cuDNN version: 8.0
GPU models and configuration: GeForce GTX 980

It fails pretty quickly, whether or not I’m using CUDA (as evidenced by checking nvidia-smi, and also backed up by the backtrace which looks the same either way).
Edit: Should have checked the PyTorch issues more carefully - this was caused by /dev/shm being too small: https://github.com/pytorch/pytorch/issues/5247 6