sgl-project/sglang · error · ValueError

hicache_storage_pass_prefix_keys must be bool, got {type(hic

Error message

hicache_storage_pass_prefix_keys must be bool, got {type(hicache_storage_pass_prefix_keys).__name__}

What it means

Validates that hicache_storage_pass_prefix_keys in the parsed extra config is strictly a bool. Python bools are required, so 0/1, "true"/"false" strings, or yes/no (which YAML may or may not coerce depending on quoting) fail the isinstance(x, bool) check.

Source

Thrown at python/sglang/srt/mem_cache/hiradix_cache.py:781

        if not isinstance(prefetch_threshold, int):
            raise ValueError(
                f"prefetch_threshold must be int, got {type(prefetch_threshold).__name__}"
            )
        if not isinstance(prefetch_timeout_base, (int, float)):
            raise ValueError(
                f"prefetch_timeout_base must be number, got {type(prefetch_timeout_base).__name__}"
            )
        if not isinstance(prefetch_timeout_per_ki_token, (int, float)):
            raise ValueError(
                f"prefetch_timeout_per_ki_token must be number, got {type(prefetch_timeout_per_ki_token).__name__}"
            )
        if not isinstance(prefetch_timeout_max, (int, float)):
            raise ValueError(
                f"prefetch_timeout_max must be number, got {type(prefetch_timeout_max).__name__}"
            )
        if not isinstance(hicache_storage_pass_prefix_keys, bool):
            raise ValueError(
                "hicache_storage_pass_prefix_keys must be bool, got "
                f"{type(hicache_storage_pass_prefix_keys).__name__}"
            )

        prefetch_timeout_config = PrefetchTimeoutConfig(
            base=float(prefetch_timeout_base),
            per_ki_token=float(prefetch_timeout_per_ki_token),
            max=float(prefetch_timeout_max),
        )

        return (
            extra_config,
            prefetch_threshold,
            prefetch_timeout_config,
            hicache_storage_pass_prefix_keys,
        )

    def reset(self):

View on GitHub (pinned to 0132848349)

Solutions

Use an unquoted boolean literal: hicache_storage_pass_prefix_keys: true (YAML) or true (JSON/TOML lowercase)
Never quote the value or substitute 1/0
Regenerate tool-produced configs so booleans stay native JSON/TOML booleans

Example fix

# before
hicache_storage_pass_prefix_keys: "true"

# after
hicache_storage_pass_prefix_keys: true

Defensive patterns

Strategy: type-guard

Validate before calling

v = cfg.get("hicache_storage_pass_prefix_keys", False)
assert isinstance(v, bool), "hicache_storage_pass_prefix_keys must be a real bool (true/false, unquoted)"

Type guard

def is_strict_bool(v) -> bool:
    return isinstance(v, bool)

Prevention

Use lowercase true/false in YAML/TOML/JSON, never quoted and never 0/1
Prefer native booleans over string flags in generated configs

When it happens

Trigger: Extra config with hicache_storage_pass_prefix_keys: "true" (quoted string), 1/0 (int), or 'yes' handled as string in TOML/JSON where only true/false booleans exist.

Common situations: Quoting booleans in YAML; using 0/1 flags from CLI-style thinking; JSON configs generated by tools that emit strings for flags; TOML requires lowercase true/false — True/TRUE in some generators become strings.

Related errors

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/3135db1ddef556a2. Report an issue: GitHub.