BoundaryML/baml · error

cargo build failed for {package}

Error message

cargo build failed for {package}

What it means

run_cargo_build runs `cargo build` for a package (e.g. the CLI) and checks the exit status; a non-zero status aborts with this message. The underlying compiler errors are printed by cargo itself to stderr before this bail.

Source

Thrown at baml_language/crates/tools_size_gate/src/measure.rs:81

        cmd.arg("--features").arg(feat);
    }

    cmd.args(extra);
    cmd.current_dir(workspace_root);

    eprintln!(
        "  building {} ({})",
        package,
        if config.no_default_features {
            "no-default-features"
        } else {
            "default features"
        }
    );

    let status = cmd.status().context("failed to run cargo build")?;
    if !status.success() {
        bail!("cargo build failed for {package}");
    }

    Ok(())
}

/// Build the CLI + pack host, then run `baml pack` on the fixture and
/// return the path to the produced standalone executable.
fn build_pack(workspace_root: &Path, name: &str, config: &ArtifactConfig) -> Result<PathBuf> {
    let pack = config.require_pack()?;

    // Build the CLI and the pack host in one release invocation. The host
    // binary must land next to the CLI in target/release so `baml pack`
    // resolves it locally (no GitHub download).
    eprintln!("  building {} + {}", pack.cli_package, pack.host_package);
    let status = Command::new("cargo")
        .arg("build")
        .arg("--release")
        .args(["-p", &pack.cli_package, "--bin", &pack.cli_bin])

View on GitHub (pinned to bd85ce9dee)

Solutions

1. Read the cargo compiler output printed above this message
2. Run `cargo build -p <package>` manually in the workspace root to reproduce
3. Fix the compile errors or restore a working tree (git stash/checkout)
4. Confirm the package and features configured for the artifact exist

Example fix

// before: broken package name in artifact config
packages = ["baml-cl”]
// after
cargo build -p baml-cli  # verify name via workspace Cargo.toml members

let status = std::process::Command::new("cargo")
    .args(["build", "-p", "baml-cli"])
    .status()?;
if !status.success() { eprintln!("preflight build failed; fix compile errors before measuring"); std::process::exit(1); }

match size_gate_result {
    Err(e) if e.to_string().starts_with("cargo build failed") => {
        eprintln!("workspace does not compile; run `cargo build` and fix errors first");
    }
    other => other?,
}

When it happens

Trigger: Any `cargo build -p <package>` failure during size-gate measure: compile errors, missing feature flags, failing build scripts, or dependency resolution errors for that package.

Common situations: Workspace code broken mid-refactor; package name typo in the size-gate config; required feature set unavailable for the target; vendored/offline dependency issues.

Understand the failure class

Background: "git command failed": what it means when a tool shells out to git and git exits non-zero — this error's family across 21 libraries.

Related errors

• cargo metadata failed
• cargo build failed for pack ({} + {})
• cargo metadata failed
• packed artifact not found (expected at {})
• artifact not found: {} (expected at {})

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/b27a99052da8f77d. Report an issue: GitHub.