BoundaryML/baml · error

{} `{}` not found.

Error message

{} `{}` not found.

What it means

This is the zero-suggestions arm of the error_not_found! macro: a named entity (class, enum, function, etc.) was looked up in the IR and not found, and no near-match candidates existed to suggest. The error states 'TYPE `NAME` not found.' with no 'did you mean' hint.

Source

Thrown at engine/baml-lib/baml-core/src/ir/ir_helpers/error_utils.rs:59

    let filtered_names = name_distances
        .iter()
        .filter(|&&(dist, _)| dist <= THRESHOLD)
        .map(|&(_, idx)| options.index(idx).as_ref());

    // Return either a limited or full set of filtered names
    match max_return {
        Some(max) => filtered_names.take(max).collect(),
        None => filtered_names.collect(),
    }
}

#[macro_export]
macro_rules! error_not_found {
    ($type:expr, $name:expr, $candidates:expr) => {{
        let suggestions =
            $crate::ir::ir_helpers::error_utils::sort_by_match($name, $candidates, Some(5));
        match suggestions.len() {
            0 => anyhow::bail!("{} `{}` not found.", $type, $name),
            1 => {
                anyhow::bail!(
                    "{} `{}` not found. Did you mean: {}?",
                    $type,
                    $name,
                    suggestions[0]
                )
            }
            _ => {
                let suggestions = suggestions.join(", ");
                anyhow::bail!(
                    "{} `{}` not found. Did you mean one of: {}?",
                    $type,
                    $name,
                    suggestions
                )
            }
        }

View on GitHub (pinned to bd85ce9dee)

Solutions

  1. Define the missing entity in a .baml file
  2. Fix the name to exactly match an existing definition (names are case-sensitive)
  3. Check that the file defining the entity is in the baml_src directory
  4. Run a listing of available classes/enums/functions to pick the right name

Example fix

// before
function A() -> UserProfil
// after
class UserProfile { id int }
function A() -> UserProfile
Defensive patterns

Strategy: validation

Validate before calling

// verify the symbol exists before referencing it
// baml CLI: list available definitions
// bazel-like check in Rust caller:
if ir.find_class(name).is_err() && ir.find_enum(name).is_err() {
  eprintln!("{} is not defined in any .baml file", name);
}

Type guard

fn symbol_exists(name: &str, ir: &Ir) -> bool {
  ir.find_class(name).is_ok() || ir.find_enum(name).is_ok() || ir.find_function(name).is_ok()
}

Try / catch

match result {
  Err(e) if e.to_string().contains("not found.") => {
    // no suggestions: name is completely unknown, fix definition or spelling
    Err(e)
  }
  other => other,
}

Prevention

When it happens

Trigger: Invoking error_not_found!("class", "Foo", candidates) from IR resolution when 'Foo' matches no definition and no candidate passes the similarity cutoff in sort_by_match.

Common situations: Completely mistyped type/function names in .baml; referencing a type after deleting its definition; working in a repo where the .baml defining the symbol was never committed.

Understand the failure class

Background: "Not found" and "does not exist" errors: why "Task not found", "No such folder", and "Can't find" fire when a lookup comes back empty — this error's family across 14 libraries.

Related errors

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/016436daae767a97. Report an issue: GitHub.