Fastai crashes on import

I’m using Python 3.8.6, fastai version 2.1.5 and pytorch version 1.8.0 . When I try to run from fastai.tabular.all import * I get

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.8/site-packages/fastai/tabular/", line 1, in <module>
    from ..basics import *
  File "/usr/local/lib/python3.8/site-packages/fastai/", line 1, in <module>
    from .data.all import *
  File "/usr/local/lib/python3.8/site-packages/fastai/data/", line 2, in <module>
    from .core import *
  File "/usr/local/lib/python3.8/site-packages/fastai/data/", line 379, in <module>
    def test_dl(self:DataLoaders, test_items, rm_type_tfms=None, with_labels=False, **kwargs):
  File "/usr/local/lib/python3.8/site-packages/fastcore/", line 116, in _f
    sig = inspect.signature(from_f)
  File "/usr/local/lib/python3.8/", line 3093, in signature
    return Signature.from_callable(obj, follow_wrapped=follow_wrapped)
  File "/usr/local/lib/python3.8/", line 2842, in from_callable
    return _signature_from_callable(obj, sigcls=cls,
  File "/usr/local/lib/python3.8/", line 2216, in _signature_from_callable
    raise TypeError('{!r} is not a callable object'.format(obj))
TypeError: None is not a callable object

Is this a known issue and what can I do about it?

I reinstalled pytorch and fastai and that seems to have helped. I’ll leave this here in case someone has a similar issue or if someone knows how to fix it without needing a reinstall.