BoundaryML/baml · critical · LspError

-32603

-32603

Error message

Internal error: {0}

What it means

LspError::Internal signals that the server violated its own invariants, panicked, or failed to serialize a response. It maps to the LSP InternalError code -32603 and prefixes the payload with 'Internal error:'. This is a bug-class error: it should never result from bad client input, only from defects or unexpected states inside baml_lsp.

Source

Thrown at baml_language/crates/baml_lsp/src/error.rs:54

    InvalidPath { path: PathBuf, message: String },
    /// The document's path is under no known source root.
    #[error("No source root contains {}", .0.display())]
    NoRootForPath(PathBuf),
    /// Cancellation claimed the response while the request was queued or
    /// running (LSP `RequestCanceled`, `-32800`).
    #[error("Request canceled: {0}")]
    RequestCanceled(String),
    /// The request's snapshot became stale under an applied source change
    /// (LSP `ContentModified`, `-32801`).
    #[error("Content modified: {0}")]
    ContentModified(String),
    /// A valid request that cannot be served right now (LSP `RequestFailed`,
    /// `-32803`).
    #[error("{0}")]
    RequestFailed(String),
    /// Violated invariants, panics, serialization (LSP `InternalError`,
    /// `-32603`).
    #[error("Internal error: {0}")]
    Internal(String),
    /// Malformed params, position, or range (LSP `InvalidParams`, `-32602`).
    #[error("Invalid params: {0}")]
    InvalidParams(String),
    /// A request before `initialize` completed (LSP `ServerNotInitialized`,
    /// `-32002`).
    #[error("Server not initialized: {0}")]
    ServerNotInitialized(String),
}

impl LspError {
    /// The one LSP error-code mapping.
    #[must_use]
    pub fn to_response_error(&self) -> lsp_server::ResponseError {
        use lsp_server::ErrorCode;
        let code = match self {
            LspError::NotificationExtractError(_)
            | LspError::RequestExtractError(_)

View on GitHub (pinned to bd85ce9dee)

Solutions

1. Capture the full message and the request that triggered it and file a bug against baml_lsp.
2. Update to the latest baml_lsp/server version, as internal errors are usually fixed in newer releases.
3. Minimize a reproducing document (the .baml content) and remove it from the project as a workaround.
4. Check server logs/stack traces around the error for the underlying panic or serialization failure.

function isInternalError(e) { return e?.code === -32603 || /Internal error:/.test(e?.message ?? ''); }

try {
  return await request(method, params);
} catch (e) {
  if (isInternalError(e)) {
    reportBug({ method, params, message: e.message }); // file against baml_lsp
    return null;
  }
  throw e;
}

When it happens

Trigger: A request handler panics on unexpected document content; serde serialization of a response fails; an invariant such as 'document must be open' or 'index must contain file' is violated.

Common situations: Edge-case .baml source triggering a parser/analysis panic; version skew between server internals and generated types; corrupted or partially-written files read during analysis.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• Function panicked: {s}
• internal error: attempted to register unknown function '%s'
• InternalError
• InternalError
• `{field_name}: int` is outside BAML int range [{}, {}], got

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/8dac663bf4057b77. Report an issue: GitHub.