{"record":{"id":"861161d967728653","repo":"vllm-project/vllm","slug":"configuration-error-0","errorCode":null,"errorMessage":"Configuration error: {0}","messagePattern":"Configuration error: (.+?)","errorType":"exception","errorClass":"BenchError","httpStatus":null,"severity":"error","filePath":"rust/src/bench/src/error.rs","lineNumber":24,"sourceCode":"#[derive(Error, Debug)]\npub enum BenchError {\n    #[error(\"HTTP request failed: {0}\")]\n    Http(#[from] reqwest::Error),\n\n    #[error(\"JSON error: {0}\")]\n    Json(#[from] serde_json::Error),\n\n    #[error(\"Tokenizer error: {0}\")]\n    Tokenizer(String),\n\n    /// The server's /tokenize//detokenize endpoint is not usable (4xx status:\n    /// not exposed, or rejected by a gateway such as LLM-d/EPP that returns\n    /// 400 instead of 404). Callers treat this as \"skip verification\", unlike\n    /// `Tokenizer` errors which are genuine failures.\n    #[error(\"tokenize endpoint unavailable: {0}\")]\n    TokenizeUnavailable(String),\n\n    #[error(\"Configuration error: {0}\")]\n    Config(String),\n\n    #[error(\"Endpoint not ready after {0}s: {1}\")]\n    EndpointTimeout(u64, String),\n\n    #[error(\"Backend error: {0}\")]\n    Backend(String),\n\n    #[error(\"IO error: {0}\")]\n    Io(#[from] std::io::Error),\n}\n\npub type Result<T> = std::result::Result<T, BenchError>;\n","sourceCodeStart":6,"sourceCodeEnd":38,"githubUrl":"https://github.com/vllm-project/vllm/blob/c794754062d49a8fdb63ab3c5215b488b865030c/rust/src/bench/src/error.rs#L6-L38","documentation":"NixlEplbCommunicator wraps each initialization step (agent creation, descriptor registration, group join) in _init_step. One of those named steps raised an exception; the original error is chained as __cause__. The {name} field identifies which init step failed.","triggerScenarios":"Any exception inside a NIXL EPLB init step, e.g. nixl agent creation failing due to bad UCX/environment setup, descriptor registration failing on invalid tensor addresses, or remote-state all-gather failures.","commonSituations":"Misconfigured UCX_TLS/IB environment variables; fabric or NIC issues on the cluster; version mismatch between the nixl wheel and installed UCX libraries.","solutions":["Inspect the chained exception (raise ... from exc) — run with the traceback to see the underlying cause under 'The above exception was the direct cause'","Check UCX/fabric env (UCX_TLS, UCX_NET_DEVICES) and NIC health if the failing step involves transport setup","Reinstall/upgrade nixl so it matches the cluster's UCX version"],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"try:\n    NixlEplbCommunicator(...)\nexcept RuntimeError as e:\n    if 'NIXL EPLB init failed' in str(e) and e.__cause__ is not None:\n        log.error('step=%s cause=%s', str(e), repr(e.__cause__))  # inspect the chained cause\n    raise","preventionTips":["Always log e.__cause__ for wrapped init failures — the real error is chained","Validate UCX env (UCX_TLS, UCX_NET_DEVICES) before first NIXL use on new clusters","Run a minimal NIXL ping-pong smoke test per node before enabling EPLB at scale"],"tags":["nixl","eplb","initialization","vllm"],"backgroundTag":null,"analyzedSha":"c794754062d49a8fdb63ab3c5215b488b865030c","analyzedAt":"2026-08-14T21:17:39.825Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}