py-call-graph incompatible with projects using torch

[gskt17]

I am trying to generate a call graph project which happens to use PyTorch. Running pycallgraph graphviz -- ./main.py, I get the following traceback:

Traceback (most recent call last):
  File "/var/www/PM-env/bin/pycallgraph", line 26, in <module>
    exec(__file_content)
  File "<string>", line 18, in <module>
  File [redacted for anonymization], in <module>
    import torch
  File "/var/www/PM-env/lib/python3.8/site-packages/torch/__init__.py", line 629, in <module>
    from .functional import *  # noqa: F403
  File "/var/www/PM-env/lib/python3.8/site-packages/torch/functional.py", line 6, in <module>
    import torch.nn.functional as F
  File "/var/www/PM-env/lib/python3.8/site-packages/torch/nn/__init__.py", line 1, in <module>
    from .modules import *  # noqa: F403
  File "/var/www/PM-env/lib/python3.8/site-packages/torch/nn/modules/__init__.py", line 2, in <module>
    from .linear import Identity, Linear, Bilinear, LazyLinear
  File "/var/www/PM-env/lib/python3.8/site-packages/torch/nn/modules/linear.py", line 6, in <module>
    from .. import functional as F
  File "/var/www/PM-env/lib/python3.8/site-packages/torch/nn/functional.py", line 1278, in <module>
    _VF.threshold_,
  File "/var/www/PM-env/lib/python3.8/site-packages/torch/_VF.py", line 25, in __getattr__
    def __getattr__(self, attr):
  File "/var/www/PM-env/lib/python3.8/site-packages/pycallgraph/tracer.py", line 24, in tracer
    self.processor.process(frame, event, arg, self.memory())
  File "/var/www/PM-env/lib/python3.8/site-packages/pycallgraph/tracer.py", line 169, in process
    module_path = module.__file__
  File "/var/www/PM-env/lib/python3.8/site-packages/torch/_VF.py", line 26, in __getattr__
    return getattr(self.vf, attr)
AttributeError: 'torch._C._VariableFunctionsClass' object has no attribute '__file__'

If I am reading this correctly, it means that pycallgraph cannot make a call graph of any project using PyTorch.

[rtarquini]

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