BoundaryML/baml · error · anyhow::Error

Failed to update runtime: {e}

Error message

Failed to update runtime: {e}

What it means

This error wraps any failure from `update_runtime` when the language server forces a runtime rebuild before handling a hover request. The BAML project's in-memory runtime (compiled from .baml files) is stale or could not be regenerated, so hover analysis cannot proceed. The original `update_runtime` error message is embedded in `{e}`.

Source

Thrown at engine/language_server/src/baml_project/mod.rs:1289

    // /// Updates (or inserts) the file content in the WASM project.
    // pub fn upsert_file(&mut self, file_path: &str, content: Option<String>) {
    //     self.baml_project.update_file(file_path, content);
    //     if self.current_runtime.is_some() {
    //         self.last_successful_runtime = self.current_runtime.take();
    //     }
    // }

    pub fn handle_hover_request(
        &mut self,
        doc: &TextDocumentItem,
        position: &Position,
        notifier: Notifier,
        feature_flags: &[String],
    ) -> anyhow::Result<Option<Hover>> {
        // Force runtime update before handling hover
        self.update_runtime(Some(notifier), feature_flags)
            .map_err(|e| anyhow::anyhow!("Failed to update runtime: {e}"))?;

        let word = get_word_at_position(&doc.text, position);
        let cleaned_word = trim_line(&word);
        if cleaned_word.is_empty() {
            return Ok(None);
        }
        let rt = self
            .runtime()
            .map_err(|e| anyhow::anyhow!("Failed to generate a runtime: {e}"))?;
        let maybe_symbol = rt.search_for_symbol(&cleaned_word);
        match maybe_symbol {
            None => Ok(None),
            Some(symbol_location) => {
                let range = Range {
                    start: Position {
                        line: symbol_location.start_line as u32,
                        character: symbol_location.start_character as u32,
                    },

View on GitHub (pinned to bd85ce9dee)

Solutions

  1. Fix the underlying compile error reported inside {e} in your .baml files (the wrapped message names the real cause).
  2. Verify the baml_src directory path is correctly configured for the workspace root.
  3. Save the broken file again after fixing so the editor triggers a fresh runtime update.
  4. Restart the language server if the project state is inconsistent after large file moves.

Example fix

// before: .baml file with type error
class Foo { name stringy }
// after: fix the type
class Foo { name string }
Defensive patterns

Strategy: try-catch

Try / catch

// Server-side wrap already in place; clients should inspect the inner error
match hover_result {
    Err(e) if e.to_string().contains("Failed to update runtime") => {
        log::warn!("runtime stale: {e}"); // surface inner cause to user
    }
    _ => {}
}

Prevention

When it happens

Trigger: Hover request (textDocument/hover) arrives and `BamlProject::update_runtime` fails — typically because baml_src files fail to compile (schema/generator errors), the baml_src path is misconfigured, or the runtime construction returns Err.

Common situations: A .baml file has a syntax or type error; the client edited files that broke the project; baml_src directory moved or was renamed so the runtime cannot be built; generator configuration invalid so runtime generation fails.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/a9c489d45bfd70f8. Report an issue: GitHub.