BoundaryML/baml · error

Failed to compute relative path from

Error message

Failed to compute relative path from {} to {}

What it means

BAML CLI deployment computes a path relative to the baml_src directory using pathdiff. When the two paths cannot be related (e.g. differing path components/windows prefixes that make a relative path impossible), it throws this error instead of producing a bogus path.

Solutions

1. Run the deploy command with paths on the same drive/filesystem as the baml_src directory
2. Pass an absolute path that shares a common ancestor with baml_src
3. Remove symlinks/mounts between the target path and baml_src and use the real path
4. On Windows, ensure both paths use the same drive letter

Example fix

// before
baml deploy --from D:\other\project
// after
baml deploy --from C:\work\my-project  # same drive as baml_src

fn is_deployable(path: &Path, baml_src: &Path) -> bool {
    pathdiff::diff_paths(path, baml_src).is_some()
}

match relative_path_to_baml_src(&p, &src) {
    Ok(rel) => use(rel),
    Err(e) => eprintln!("Cannot make path relative to baml_src: {e:#}"),
}

When it happens

Trigger: Calling deploy (relative_path_to_baml_src via deploy_project_no_progress_spinner) with a path argument that is not on the same filesystem root/prefix as the resolved baml_src directory, such as passing an absolute Windows path with a different drive, or a path that is not under/related to the project root.

Common situations: Running `baml deploy` from a different drive (C:\ vs D:\ on Windows), symlinking the baml_src directory across mounts, or passing an --from path outside the project tree.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• BAML project already exists
• cannot determine directory of current executable
• ` ` doesn't look like it belongs to a BAML project — no…
• Expected --from ' ' to be a baml_src/ directory, but it…
• Expected --from ' ' to be a baml_src/ directory, but it is…

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/c11939f3fe89a80f. Report an issue: GitHub.

Appendix: source

Thrown at engine/cli/src/deploy.rs:44

// Constants (replace with actual values as needed)
#[derive(clap::Args, Debug)]
pub struct DeployArgs {
    #[arg(long, help = "path/to/baml_src", default_value = "./baml_src")]
    pub(super) from: PathBuf,

    #[arg(
        long,
        env = "NEXT_PUBLIC_BOUNDARY_API_URL",
        default_value = "https://api2.boundaryml.com",
        hide = true
    )]
    pub(super) api_url: String,
}

fn relative_path_to_baml_src(path: &Path, baml_src: &Path) -> Result<PathBuf> {
    pathdiff::diff_paths(path, baml_src).ok_or_else(|| {
        anyhow::anyhow!(
            "Failed to compute relative path from {} to {}",
            path.display(),
            baml_src.display()
        )
    })
}

impl DeployArgs {
    /// Implementation notes:
    ///
    ///   - selected dialoguer / indicatif based on https://fadeevab.com/comparison-of-rust-cli-prompts/
    pub async fn run_async(
        &self,
        feature_flags: internal_baml_core::feature_flags::FeatureFlags,
    ) -> Result<()> {
        let runtime =
            BamlRuntime::from_directory(&self.from, std::env::vars().collect(), feature_flags)
                .context("Failed to build BAML runtime")?;

View on GitHub (pinned to bd85ce9dee)