BoundaryML/baml · error

BAML toolchain is corrupt: VERSION contains . Run: baml…

Error message

BAML toolchain {version} is corrupt: VERSION contains {}.
Run: baml toolchain install {version} --force

What it means

Integrity check failure: the wrapper reads the VERSION file inside an installed toolchain's directory and compares it to the directory name. A mismatch means the installation is corrupt — the directory was renamed, partially overwritten, or the files were copied between version directories. The toolchain is not trusted to run in this state.

Solutions

1. Reinstall over the corrupt copy: `baml toolchain install <version> --force`
2. If it recurs, delete the toolchain directory manually and reinstall to rule out a partially-copied download

When it happens

Trigger: Thrown at baml_language/crates/baml/src/main.rs:683 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/ebdb19f4b1f774d9. Report an issue: GitHub.

Appendix: source

Thrown at baml_language/crates/baml/src/main.rs:683

}

fn toolchain_cli_path(version: &str) -> PathBuf {
    toolchains_dir()
        .join(version)
        .join("bin")
        .join(cli_exe_name())
}

fn verify_toolchain_version_file(version: &str) -> Result<()> {
    let path = toolchains_dir().join(version).join("VERSION");
    let actual = fs::read_to_string(&path).with_context(|| {
        format!(
            "failed to read toolchain VERSION file at {}",
            path.display()
        )
    })?;
    if actual.trim() != version {
        anyhow::bail!(
            "BAML toolchain {version} is corrupt: VERSION contains {}.\nRun: baml toolchain install {version} --force",
            actual.trim()
        );
    }
    Ok(())
}

fn is_channel(selector: &str) -> bool {
    selector == "canary" || selector == "nightly"
}

/// Whether a selector names a local `baml-cli` binary rather than a channel or
/// a version. Channels and versions never contain a path separator, so a bare
/// path is unambiguous and needs no prefix or flag to mark it.
fn is_path_selector(selector: &str) -> bool {
    is_path_selector_on(selector, cfg!(windows))
}

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