Hi!

I’ experimenting with converting Pytorch models to ONNX using this repository(repo) - It is basically implementation of SSD.

Tracer argues at this script that computes coordinates for prior boxes.(script)

Specifically this code - where tensor is converted into python range:

```
for i, j in product(range(f), repeat=2):
f_k = self.image_size / self.steps[k]
# unit center x,y
cx = (j + 0.5) / f_k
cy = (i + 0.5) / f_k
```

After that the whole process hangs. Any idea what might cause this or suggestions how to rewrite this part?

Thanks a lot for your help!