{"record":{"id":"c184c8de837fc7af","repo":"openai/codex","slug":"creating-http-server-err","errorCode":null,"errorMessage":"creating HTTP server: {err}","messagePattern":"creating HTTP server: (.+?)","errorType":"exception","errorClass":"anyhow::Error","httpStatus":null,"severity":"error","filePath":"codex-rs/responses-api-proxy/src/lib.rs","lineNumber":101,"sourceCode":"        HeaderValue::from_str(&host).context(\"constructing Host header from upstream URL\")?;\n\n    let forward_config = Arc::new(ForwardConfig {\n        upstream_url,\n        host_header,\n    });\n    let dump_dir = args\n        .dump_dir\n        .map(ExchangeDumper::new)\n        .transpose()\n        .context(\"creating --dump-dir\")?\n        .map(Arc::new);\n\n    let (listener, bound_addr) = bind_listener(args.port)?;\n    if let Some(path) = args.server_info.as_ref() {\n        write_server_info(path, bound_addr.port())?;\n    }\n    let server = Server::from_listener(listener, None)\n        .map_err(|err| anyhow!(\"creating HTTP server: {err}\"))?;\n    let client = Arc::new(\n        Client::builder()\n            // Disable reqwest's 30s default so long-lived response streams keep flowing.\n            .timeout(None::<Duration>)\n            .build()\n            .context(\"building reqwest client\")?,\n    );\n\n    eprintln!(\"responses-api-proxy listening on {bound_addr}\");\n\n    let http_shutdown = args.http_shutdown;\n    for request in server.incoming_requests() {\n        let client = client.clone();\n        let forward_config = forward_config.clone();\n        let dump_dir = dump_dir.clone();\n        std::thread::spawn(move || {\n            if http_shutdown && request.method() == &Method::Get && request.url() == \"/shutdown\" {\n                let _ = request.respond(Response::new_empty(StatusCode(200)));","sourceCodeStart":83,"sourceCodeEnd":119,"githubUrl":"https://github.com/openai/codex/blob/339751715c64496cb86246bfb3935f40e309dd3d/codex-rs/responses-api-proxy/src/lib.rs#L83-L119","documentation":"After bind_listener succeeds, run_main wraps the listener with Server::from_listener. If constructing the server from the listener fails (socket option setup, internal task spawn), the error is wrapped as 'creating HTTP server: {err}' with the underlying cause carried in the message suffix.","triggerScenarios":"Server::from_listener returning Err right after a successful bind - for example failure configuring the accepted socket, a runtime/task spawn failure, or a listener handle in an invalid state.","commonSituations":"File-descriptor exhaustion (EMFILE) around accept-loop setup; restricted sandboxes blocking socket option calls; rare fork/exec edge cases. The common startup failure 'failed to bind {addr}' happens earlier and is a different error.","solutions":["Read the text after 'creating HTTP server:' - it contains the real io/runtime error","Check and raise file-descriptor limits (ulimit -n) if the process is near exhaustion","Restart the proxy; transient setup failures usually clear on retry","If reproducible, capture full stderr and report upstream with the wrapped cause"],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"match run_main(args).await {\n    Ok(()) => {}\n    Err(e) if e.to_string().starts_with(\"creating HTTP server\") => {\n        eprintln!(\"proxy failed to initialize server: {e:#}\");\n        std::process::exit(1);\n    }\n    Err(e) => { eprintln!(\"proxy error: {e:#}\"); std::process::exit(1); }\n}","preventionTips":["Run the proxy with generous file-descriptor limits","Supervise with restart-on-failure and backoff","Distinguish from 'failed to bind' - bind failures need a port change; from_listener failures usually need an environment fix"],"tags":["rust","http-server","startup","networking"],"backgroundTag":"server-startup-failed","analyzedSha":"339751715c64496cb86246bfb3935f40e309dd3d","analyzedAt":"2026-08-25T05:35:09.876Z","schemaVersion":2},"datasetVersion":"2026-08-25T06:17:31.827Z"}