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vllm - ✅(Solved) Fix [Bug]: Unblock PyTorch C++20 Migration [1 pull requests]

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Fix Action

Fixed

PR fix notes

PR #40380: Require C++20 for compatibility with PyTorch

Description (problem / solution / changelog)

Summary

PyTorch headers now enforce C++20 as a minimum (torch/all.h and ATen/ATen.h emit a #error if __cplusplus < 202002L). Building vLLM against such a PyTorch fails because vLLM's build system was still setting C++17.

  • CMakeLists.txt: CMAKE_CXX_STANDARD 17 → 20
  • cmake/cpu_extension.cmake: same
  • cmake/external_projects/deepgemm.cmake: -std=c++17 → -std=c++20

Changed files

  • CMakeLists.txt (modified, +1/-1)
  • cmake/cpu_extension.cmake (modified, +1/-1)
  • cmake/external_projects/deepgemm.cmake (modified, +1/-1)
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Your current environment

N/A

🐛 Describe the bug

Per https://github.com/pytorch/pytorch/issues/176662 - PyTorch is moving to C++20.

Please upgrade vLLM to C++20 as well to maintain compatibility.

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extent analysis

TL;DR

Upgrade vLLM to C++20 to maintain compatibility with PyTorch.

Guidance

  • Check the vLLM documentation for specific instructions on how to upgrade to C++20.
  • Verify that your development environment supports C++20 and make any necessary adjustments.
  • Review the PyTorch issue #176662 for any additional information on the C++20 transition.

Notes

The upgrade to C++20 may require changes to your code or dependencies, so be sure to test thoroughly after upgrading.

Recommendation

Apply workaround: Upgrade to C++20 to ensure compatibility with the latest PyTorch version.

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vllm - ✅(Solved) Fix [Bug]: Unblock PyTorch C++20 Migration [1 pull requests]