[Python] fastai.vision Import Error: How to fix the import error so I can use...

I'm working on google colab ( python 3.6 and GPU), I import torch (1.2.0) nicely and I use the following to import fastai:

import fastai
print(fastai.__version__)
from fastai import *
from fastai.vision import *


I get the following error:

ImportError: /usr/local/lib/python3.6/dist-packages/torchvision/_C.cpython-36m-x86_64-linux-gnu.so: undefined symbol: _ZN3c106Device8validateEv

I have tried to install different torch versions like 1.0.0 and work with earlier python versions. I have also tried to install fastai and its dependencies manually using !pip, but nothing worked.

This is the complete code I used to install torch:

from os.path import exists
from wheel.pep425tags import get_abbr_impl, get_impl_ver, get_abi_tag

platform = '{}{}-{}'.format(get_abbr_impl(), get_impl_ver(),
get_abi_tag())
cuda_output = !ldconfig -p|grep cudart.so|sed -e 's/.*\.\([0-9]*\)\.\
([0-9]*\)$/cu\1\2/'
accelerator = cuda_output[0] if exists('/dev/nvidia0') else 'cpu'

!pip install torch_nightly -f
https://download.pytorch.org/whl/nightly/{accelerator}/torch_nightly.html
!pip install fastai

import torch

print(torch.__version__)
print(torch.cuda.is_available())
print(torch.backends.cudnn.enabled)


And this is the full error message I get:

ImportError
Traceback (most recent call last)
<ipython-input-5-4b8b8d8134df> in <module>()
2 print(fastai.__version__)
3 from fastai import *
----> 4 from fastai.vision import *
8 frames
/usr/local/lib/python3.6/dist-packages/torchvision/ops/boxes.py in
<module>()
1 import torch
----> 2 from torchvision import _C
3
4
5 def nms(boxes, scores, iou_threshold):

ImportError: /usr/local/lib/python3.6/dist-
packages/torchvision/_C.cpython-36m-x86_64-linux-gnu.so: undefined
symbol: _ZN3c106Device8validateEv


I'm unable to use ImageDataBunch.from_folder because of this fastai import error. I get the error NameError: name 'ImageDataBunch' is not defined when I do.

Note: I did use the same code before and I was able to use fastai and ImageDataBunch.from_folder with no import errors , but I'm guessing that an update to fastai or torch happened.

Continue reading...