torch2trt causes nano to freeze

I installed torch2trt from GitHub
My nano freezes executing line 12 of the following example.

import torch
from torch2trt import torch2trt
from torchvision.models.alexnet import alexnet

# create some regular pytorch model...
model = alexnet(pretrained=True).eval().cuda()

# create example data
x = torch.ones((1, 3, 224, 224)).cuda()

# convert to TensorRT feeding sample data as input
model_trt = torch2trt(model, [x])

I have re-installed several times. Any suggestions?

The release page is

There are several PyTorch versions. Please share the version of your PyTorch and the release version( $ head -1 /etc/nv_tegra_release ) for reference.