BoundaryML/baml · error · LspError

{0}

Error message

{0}

What it means

LspError::NotificationExtractError wraps an lsp_server::ExtractError<Notification> raised when an incoming LSP notification cannot be deserialized or matched to a known method. thiserror renders it transparently with `{0}`. It is reported through LspError::to_response_error.

Source

Thrown at baml_language/crates/baml_lsp/src/error.rs:11

//! The one LSP error type and its JSON-RPC code table.

use std::path::PathBuf;

/// Every failure a request or notification handler can report.
///
/// Serialized to the wire exclusively through [`LspError::to_response_error`];
/// the legacy `-32001 UnknownErrorCode` is never emitted.
#[derive(Debug, thiserror::Error)]
pub enum LspError {
    #[error("{0}")]
    NotificationExtractError(lsp_server::ExtractError<lsp_server::Notification>),
    #[error("Notification not supported: {0}")]
    NotificationNotSupported(String),
    #[error("{0}")]
    RequestExtractError(lsp_server::ExtractError<lsp_server::Request>),
    #[error("Request not supported: {0}")]
    RequestNotSupported(String),
    #[error("Failed to serialize request result: {0}")]
    RequestSerializeError(serde_json::Error),
    /// The client's sink is gone; nothing more can be delivered.
    #[error("Client closed")]
    ClientClosed,
    /// Bounded transport backpressure (LSP `RequestFailed`, `-32803`).
    #[error("LSP outbound sink is saturated")]
    OutboundSaturated,
    /// A frame larger than the transport limit (LSP `RequestFailed`,
    /// `-32803`).
    #[error("LSP outbound frame exceeds the transport limit")]

View on GitHub (pinned to bd85ce9dee)

Solutions

1. Check that the LSP client and server speak compatible LSP versions and schemas
2. Log the raw notification payload to identify the malformed field
3. Verify no custom notifications are being sent without matching registration

fn is_notification_extract_err(e: &LspError) -> bool {
    matches!(e, LspError::NotificationExtractError(_))
}

match result {
    Err(LspError::NotificationExtractError(e)) => log::warn!("bad notification: {e}"),
    other => other?,
}

When it happens

Trigger: A notification arrives with a JSON body that fails serde deserialization into the expected lsp_server::Notification shape, or a handler calls an extraction API on a message that is not the expected notification.

Common situations: A client/server version mismatch producing unknown notification payloads; malformed JSON-RPC frames from a buggy client; custom extensions sending nonstandard notification shapes.

Related errors

• Notification not supported: {0}
• Request not supported: {0}
• Failed to serialize request result: {0}
• no filesystem is attached to this server ({})
• Client closed

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/6c63d58999fed6ac. Report an issue: GitHub.