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As of commit e594ec0 with merge base 1655d0a ():

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Note: the commit author shows jalilAlva (another account I have) due to a local git config mistake. This PR was opened and authored by jvz37, my the account registered for Docathon 2026.

@claude

Claude finished @sekyondaMeta's task in 1m 44s —— View job

Review of PR #3885

• Gather context and read changed files
• Review code changes against origin/main
• Post review feedback

Summary

This PR modernizes polynomial_custom_function.py with two changes: (1) splitting forward(ctx, input) into forward(input) + setup_context(ctx, inputs, output), and (2) replacing hardcoded device with torch.accelerator. Both changes are correct and align with PyTorch 2.0+ recommendations.

Issues Found

1. Trailing whitespace on line 39 (minor, will likely fail CI lint)

        return 0.5 * (5 * input ** 3 - 3 * input)
    ←── trailing spaces here
    @staticmethod

Line 39 contains trailing whitespace between the forward method and setup_context. This will be caught by lintrunner.

Fix this →

2. Device selection pattern inconsistency with sibling tutorial (nit)

The sibling file polynomial_autograd.py (line 23-24) uses:

device = torch.accelerator.current_accelerator().type if torch.accelerator.is_available() else "cpu"
print(f"Using {device} device")
torch.set_default_device(device)

This PR's version wraps the same logic in parentheses (multi-line) which is fine stylistically, but it omits the explanatory comment and print statement that help learners understand what's happening. Consider adding:

• A comment explaining accelerator selection (as in polynomial_autograd.py line 19)
• A print(f"Using {device} device") statement for learner feedback

This is purely a suggestion for tutorial pedagogical consistency — the code is functionally correct without it.

What Looks Good

• The forward / setup_context split is implemented correctly per the PyTorch docs.
• The backward method is unchanged and remains correct.
• The input, = inputs unpacking in setup_context is idiomatic.
• The torch.accelerator API usage is correct.

Verdict

Looks good overall. The trailing whitespace on line 39 should be fixed before merge (it will likely fail lint CI). The other suggestion about matching the sibling tutorial's style is optional.