onnx: Onnx Caffe2 conflict - Causes segmentation fault

I’m trying to use onnx with caffe2, but when I try to import core from caffe2.python and onnx in the same python script I get a segmentation fault. e.g. from caffe2.python import core alone works fine import onnx alone works fine as well, but when I do from caffe2.python import core import onnx I get a segmentation fault. Same thing when I switch the order. Is there anyone who has encountered a similar problem or who has an idea how to track the conflict?