sgl-project/sglang · warning · DeprecationWarning

Environment variable '{self.deprecated_name}' is deprecated;

Error message

Environment variable '{self.deprecated_name}' is deprecated; use '{self.name}' instead. The alias will be removed in a future release.

What it means

A LegacyEnvVar alias (old SGL_-prefixed name or other legacy alias) was found in the environment while the canonical SGLANG_ name was unset. The value is honored via the alias, but a DeprecationWarning announces the alias will be removed.

Source

Thrown at python/sglang/srt/environ.py:172

class _DeprecatedEnvFallback:
    """Mixin for EnvField subclasses: if the canonical env var is not set,
    check *deprecated_name* and emit DeprecationWarning before reading it.

    Usage:
        SGLANG_DSA_FUSE_TOPK = EnvBoolWithAlias(True, deprecated_name="SGLANG_NSA_FUSE_TOPK")
    """

    def __init__(self, default: Any, deprecated_name: str, secret: bool = False):
        super().__init__(default, secret=secret)
        self.deprecated_name = deprecated_name

    def get(self) -> Any:
        if os.getenv(self.name) is None:
            fallback = os.getenv(self.deprecated_name)
            if fallback is not None:
                warnings.warn(
                    f"Environment variable '{self.deprecated_name}' is deprecated; "
                    f"use '{self.name}' instead. "
                    "The alias will be removed in a future release.",
                    DeprecationWarning,
                    stacklevel=2,
                )
                os.environ[self.name] = fallback
        return super().get()


class EnvBoolWithAlias(_DeprecatedEnvFallback, EnvBool):
    pass


class EnvIntWithAlias(_DeprecatedEnvFallback, EnvInt):
    pass

View on GitHub (pinned to 0132848349)

Solutions

1. Rename the variable in your environment/Dockerfile/manifest to the canonical SGLANG_ name shown in the message
2. Grep deployment configs for the deprecated alias and update all occurrences
3. Unset the alias to confirm nothing silently depends on it

Example fix

# before
export SGL_ENABLE_JIT_DEEPGEMM=1
# after
export SGLANG_ENABLE_JIT_DEEPGEMM=1

import re
for k in list(os.environ):
    if k.startswith("SGL_"):
        os.environ["SGLANG_" + k[4:]] = os.environ.pop(k)

When it happens

Trigger: Exporting a deprecated alias name (e.g. SGL_CACHE_PATH style legacy key) without setting its canonical SGLANG_ replacement, then reading it via envs.<VAR>.get().

Common situations: Old Docker images or launch scripts carrying pre-rename env names; copy-pasted configs from before an sglang env-var rename.

Related errors

• Environment variable {old_name} is deprecated. Please use {s
• Environment variable {key} is deprecated, please use {new_ke
• 'python -m sglang.launch_server' is still supported, but 'sg
• 'data_parallel_rank' is deprecated, use 'routed_dp_rank' ins
• 'data_parallel_rank' is deprecated, use 'routed_dp_rank' ins

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/572886cfd0411856. Report an issue: GitHub.