BoundaryML/baml · error · SourceRootError

dependency ` ` names a source root that does not exist

Error message

dependency `{name}` names a source root that does not exist

What it means

Part of `SourceRootError` returned by `ProjectDatabase::add_source_root` / `add_dependency`. A dependency edge references a root `name` that is not a live source root in the database. Dependency edges must point at roots that have already been added.

Solutions

1. Add the dependency target's source root first (dependency order), then add the dependent root.
2. Verify the dependency name matches an existing root exactly (spelling/case).
3. If the target was removed, drop or update the stale dependency edge.

Example fix

// before
db.add_source_root(app_spec.depending_on(vec![Dependency { name: "core".into(), .. }]))?; // core not added yet
// after
db.add_source_root(core_spec)?;
db.add_source_root(app_spec.depending_on(vec![Dependency { name: "core".into(), .. }]))?;

fn deps_exist(deps: &[Dependency], db: &ProjectDatabase) -> Result<(), String> {
    for d in deps {
        if db.find_source_root(&d.name).is_none() {
            return Err(format!("dependency `{}` is not a live root", d.name));
        }
    }
    Ok(())
}

match db.add_source_root(spec) {
    Err(SourceRootError::UnknownDependencyRoot { name }) => eprintln!("add root `{name}` first"),
    Err(e) => eprintln!("root error: {e}"),
    Ok(root) => root,
}

When it happens

Trigger: Calling `add_source_root` with `depending_on` where a `Dependency.root` name (or the referenced root) does not correspond to any root currently registered via `add_source_root`.

Common situations: Adding a project root that depends on another package before that package's root is installed; typos in dependency names; removing a root while other roots still depend on it.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• dependency ` ` is declared twice
• dependency ` ` would form a dependency cycle
• {0}
• {0}
• {0}

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/c9019a5740db8211. Report an issue: GitHub.

Appendix: source

Thrown at baml_language/crates/baml_db/src/db.rs:97

}

/// Why [`ProjectDatabase::add_source_root`] or
/// [`ProjectDatabase::add_dependency`] refused.
#[derive(Debug, Clone, PartialEq, Eq, thiserror::Error)]
pub enum SourceRootError {
    /// A live root already sits at this (canonical) path.
    #[error("a source root already exists at this path")]
    PathTaken(SourceRoot),
    /// The edge name is one no package may declare: a stdlib package's name
    /// (already an implicit edge of every package) or a source-level
    /// qualifier (`root`, `env`).
    #[error("dependency name `{name}` is reserved")]
    ReservedDependencyName { name: Name },
    /// The root already has an edge under this name.
    #[error("dependency `{name}` is declared twice")]
    DuplicateDependencyName { name: Name },
    /// The edge names a root that is not live in this database.
    #[error("dependency `{name}` names a source root that does not exist")]
    UnknownDependencyRoot { name: Name },
    /// The edge would make the dependency graph cyclic.
    #[error("dependency `{name}` would form a dependency cycle")]
    DependencyCycle { name: Name },
    /// The interface bytes are not a valid `PackageInterface` artifact.
    #[error("invalid package interface: {message}")]
    InvalidInterface { message: String },
}

/// The main database for BAML projects.
///
/// `ProjectDatabase` owns the Salsa storage directly and implements all the
/// compiler `Db` traits. It provides high-level APIs for:
/// - Source-root management (add/remove roots, longest-prefix lookup)
/// - File management within a root (add/update/remove files)
/// - Diagnostics collection via `check()`
///
/// ## Example

View on GitHub (pinned to bd85ce9dee)