[Bug] Afar not working with cudf/dask-cudf/gpu-numba

[ncclementi]

When trying to use afar with cudf, it's not working the problem seems to be with numba when using gpu (numba jit by itself has no problems)

Minimal reproducible example:

with afar.run, remotely:
    import cudf
    x = str(cudf)

x.result() retrieves

AttributeError: 'LocalPrint' object has no attribute '__name__'

after looking into the traceback

import traceback

traceback.print_tb(x.traceback())

I get the following:

  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/afar/_core.py", line 337, in run_afar
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/innerscope/core.py", line 492, in __call__
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/innerscope/core.py", line 541, in _call
  File "<afar>", line 2, in _afar_magic_
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/cudf/__init__.py", line 4, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/cudf/utils/gpu_utils.py", line 18, in validate_setup
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/rmm/__init__.py", line 16, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/rmm/mr.py", line 2, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/rmm/_lib/__init__.py", line 3, in <module>
  File "rmm/_lib/device_buffer.pyx", line 1, in init rmm._lib.device_buffer
  File "rmm/_cuda/stream.pyx", line 26, in init rmm._cuda.stream
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/__init__.py", line 39, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/core/decorators.py", line 12, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/stencils/stencil.py", line 11, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/core/registry.py", line 4, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/core/dispatcher.py", line 16, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/core/compiler.py", line 6, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/core/callconv.py", line 12, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/core/base.py", line 24, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/cpython/builtins.py", line 511, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/core/typing/builtins.py", line 22, in <module>
  File "/opt/conda/envs/rapids/lib/python3.8/site-packages/numba/core/typing/templates.py", line 1157, in register_global

I'm using numba=0.53 which line 1157 corresponds to the following https://github.com/numba/numba/blob/release0.53/numba/core/typing/templates.py#L1157-L1159

Which is trying to get .__name__ from LocalPrint

Looking at this all issue numpy/numpy#3112 (comment) it seems that in the numba end (https://github.com/numba/numba/blob/97fe221b3704bd17567b57ea47f4fc6604476cf9/numba/core/typing/templates.py#L1161-L1163) they are not updating the wraper as suggested here https://docs.python.org/3.3/library/functools.html#functools.update_wrapper, meaning that it is not assigning __name__ to LocalPrint when it gets there.

I wonder if there is a way of fixing this on afar maybe on LocalPrint().

[eriknw]

Oh no!

Thanks for the excellent bug report (and for using afar!). I'll see what I can do.

Perhaps LocalPrint could mock itself as builtins.print by setting it's __module__ and __name__ attribute as such. Far from being hacky and sinful, this may actually be a reasonable thing to do.

[jcrist]

Perhaps LocalPrint could mock itself as builtins.print by setting it's module and name attribute as such. Far from being hacky and sinful, this may actually be a reasonable thing to do.

That might work. Another option would be to spoof sys.stdout as a threadlocal IO type and leave print alone. When no file is passed to print, it will dynamically getattr(sys, "stdout") every call, letting you still capture stdout without modifying builtins.

[eriknw]

Release version 0.6.1 with the easy fix 🤞 . On PyPI, and should be available from conda-forge soon.

Heh, I don't know whether to be proud or embarrassed by afar's code. It's... something. But, it works, and it brings me laughter 😂 !

[ncclementi]

@eriknw awesome, we'll give it a try soon and I'll keep you updated!
Cheers to bringing laughter 😂 !

Edit: tried it and indeed it worked! Thank you for your work!