python3Packages.vllm: fix Blackwell support (#455364)

    hash = "sha256-HJY+Go1viPkSVZPEs/NyMtYJzas4mMLiIZF3kNX+WgA=";

  };

  # FlashMLA's Blackwell (SM100) kernels were developed against CUTLASS v3.9.0

  # (since https://github.com/vllm-project/FlashMLA/commit/9c5dfab6d1746b4a27af14f440e7afd5c01ece68)

  # and are currently incompatible with CUTLASS v4.x APIs. The rest of the vLLM

  # build uses a newer CUTLASS, so we package both versions.

  # See upstream issue: https://github.com/vllm-project/vllm/issues/27425

  # See git submodule commit at:

  # https://github.com/vllm-project/FlashMLA/tree/${flashmla.src.rev}/csrc

  cutlass-flashmla = fetchFromGitHub {

    owner = "NVIDIA";

    repo = "cutlass";

    tag = "v3.9.0";

    hash = "sha256-Q6y/Z6vahASeSsfxvZDwbMFHGx8CnsF90IlveeVLO9g=";

  };

  flashmla = stdenv.mkDerivation {

    pname = "flashmla";

    # https://github.com/vllm-project/FlashMLA/blob/${src.rev}/setup.py

    # flashmla normally relies on `git submodule update` to fetch cutlass

    buildPhase = ''

      rm -rf csrc/cutlass

      ln -sf ${cutlass} csrc/cutlass

      ln -sf ${cutlass-flashmla} csrc/cutlass

    '';

    installPhase = ''

        "8.9"

        "9.0"

        "9.0a"

        # Blackwell (SM100+) capabilities temporarily disabled due to CUTLASS API incompatibility

        # FlashMLA kernels require CUTLASS v4.2.1+ APIs not available in bundled v4.0.0

        # TODO: Re-enable when vLLM upgrades CUTLASS (see https://github.com/vllm-project/vllm/pull/24673)

        # "10.0"

        # "10.0a"

        # "10.1"

        # "10.1a"

        # "10.3"

        # "10.3a"

        # "12.0"

        # "12.0a"

        # "12.1"

        # "12.1a"

        "10.0"

        "10.0a"

        "10.1"

        "10.1a"

        "10.3"

        "10.3a"

        "12.0"

        "12.0a"

        "12.1"

        "12.1a"

      ];

      ptx = lists.map (x: "${x}+PTX") real;

    in