vllm-project/vllm · error · ValueError

Invalid syntax '{op}' for custom op, must be 'all', 'none',

Error message

Invalid syntax '{op}' for custom op, must be 'all', 'none', '+op' or '-op' (where 'op' is the registered op name)

What it means

CompilationConfig.custom_ops selects which custom ops stay enabled under compilation, using a small grammar: exactly one base mode ('all' or 'none') plus optional '+op'/'-op' entries naming registered ops. Entries that are neither the base modes nor a >=2-character string starting with '+' or '-' raise ValueError.

Source

Thrown at vllm/config/compilation.py:1000

            and not current_platform.is_cpu()
        ):
            # use horizontal fusion, which is useful for fusing qk-norm and
            # qk-rope when query and key have different shapes.
            self.inductor_compile_config["combo_kernels"] = True
            self.inductor_compile_config["benchmark_combo_kernel"] = True

        if self.use_inductor_graph_partition and not is_torch_equal_or_newer(
            "2.9.0.dev"
        ):
            raise ValueError(
                "use_inductor_graph_partition is only "
                "supported with torch>=2.9.0.dev. Set "
                "use_inductor_graph_partition=False instead."
            )

        for op in self.custom_ops:
            if op not in {"all", "none"} and (len(op) < 2 or op[0] not in {"+", "-"}):
                raise ValueError(
                    f"Invalid syntax '{op}' for custom op, "
                    "must be 'all', 'none', '+op' or '-op' "
                    "(where 'op' is the registered op name)"
                )

        base_modes = [op for op in self.custom_ops if op in {"all", "none"}]
        if len(base_modes) > 1:
            raise ValueError(
                "custom_ops can contain only one base mode: 'all' or 'none'"
            )

        enabled_ops = {op[1:] for op in self.custom_ops if op.startswith("+")}
        disabled_ops = {op[1:] for op in self.custom_ops if op.startswith("-")}
        conflicting_ops = sorted(enabled_ops & disabled_ops)
        if conflicting_ops:
            raise ValueError(
                "custom_ops cannot both enable and disable the same operation(s): "
                f"{', '.join(conflicting_ops)}. Remove either the '+' or '-' directive"

View on GitHub (pinned to c794754062)

Solutions

1. Use '+opname' to enable an op on top of the base mode, '-opname' to disable one, e.g. custom_ops=['none', '+rms_norm'].
2. Keep exactly one base mode ('all' or 'none') in the list.
3. Verify the op name matches a registered custom op.

Example fix

# before
CompilationConfig(custom_ops=['rms_norm', 'all'])
# after
CompilationConfig(custom_ops=['all', '-rms_norm'])

import re
VALID = re.compile(r'^(all|none|[+-].+)$')
def valid_custom_ops(ops: list[str]) -> bool:
    base = [o for o in ops if o in ('all', 'none')]
    return len(base) <= 1 and all(VALID.match(o) for o in ops)

def is_valid_custom_ops(value) -> bool:
    if not isinstance(value, (list, tuple, set)):
        return False
    base = [o for o in value if o in ('all', 'none')]
    return len(base) <= 1 and all(o in ('all', 'none') or (len(o) >= 2 and o[0] in '+-') for o in value)

When it happens

Trigger: Passing CompilationConfig(custom_ops=['rms_norm']) (op name without sign prefix), ['*'], or ['ALL'] — anything not 'all', 'none', '+op' or '-op' — during config validation.

Common situations: Forgetting the +/- prefix when enabling/disabling a specific op; using uppercase 'All'; passing an empty string; listing the same op with both signs or multiple base modes.

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AI-assisted analysis of vllm-project/vllm@c794754062 (2026-08-14). Data as JSON: /api/errors/ab4ee3e9e9560d11. Report an issue: GitHub.