zed-industries/zed · error · anyhow::Error

missing or invalid `request` field in config. Expected 'laun

Error message

missing or invalid `request` field in config. Expected 'launch' or 'attach'

What it means

request_kind reads the debug config JSON to classify it as 'launch' or 'attach'; if the `request` field is missing or holds another value, the kind cannot be determined and this validation error is returned. The task's debug configuration JSON is the input at fault.

Source

Thrown at crates/dap/src/adapters.rs:379

        cx: &mut AsyncApp,
    ) -> Result<DebugAdapterBinary>;

    /// Returns the language name of an adapter if it only supports one language
    fn adapter_language_name(&self) -> Option<LanguageName> {
        None
    }

    /// Extracts the kind (attach/launch) of debug configuration from the given JSON config.
    /// This method should only return error when the kind cannot be determined for a given configuration;
    /// in particular, it *should not* validate whether the request as a whole is valid, because that's best left to the debug adapter itself to decide.
    async fn request_kind(
        &self,
        config: &serde_json::Value,
    ) -> Result<StartDebuggingRequestArgumentsRequest> {
        match config.get("request") {
            Some(val) if val == "launch" => Ok(StartDebuggingRequestArgumentsRequest::Launch),
            Some(val) if val == "attach" => Ok(StartDebuggingRequestArgumentsRequest::Attach),
            _ => Err(anyhow!(
                "missing or invalid `request` field in config. Expected 'launch' or 'attach'"
            )),
        }
    }

    fn dap_schema(&self) -> serde_json::Value;

    fn label_for_child_session(&self, _args: &StartDebuggingRequestArguments) -> Option<String> {
        None
    }

    fn compact_child_session(&self) -> bool {
        false
    }

    fn prefer_thread_name(&self) -> bool {
        false
    }

View on GitHub (pinned to f4178619ac)

Solutions

1. Set "request": "launch" or "attach" in the debug scenario/task JSON
2. Fix typos in the request field of the adapter config

When it happens

Trigger: Thrown at crates/dap/src/adapters.rs:379 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of zed-industries/zed@f4178619ac (2026-08-20). Data as JSON: /api/errors/266bc80494345d1a. Report an issue: GitHub.