BoundaryML/baml · error · BamlSysError

Platform not supported

Error message

Platform not supported: {os}/{arch}

What it means

`BamlSysError::UnsupportedPlatform` from baml-sys: the loader was asked to find/load a BAML library on an OS/architecture combination it has no prebuilt artifact or mapping for. The message names the offending `os`/`arch`.

Solutions

1. Run on a supported platform (e.g. linux/darwin/windows on x86_64 or aarch64)
2. Build the native BAML library from source for your platform and supply it via the search paths
3. Contribute/add a platform mapping and prebuilt artifact for the target

Example fix

// before
# running on freebsd/x86 -> UnsupportedPlatform: freebsd/x86
// after
# run under supported linux-x86_64 container: docker run --platform linux/amd64 ...

let (os, arch) = (std::env::consts::OS, std::env::consts::ARCH);
const SUPPORTED: &[(&str, &str)] = &[("linux","x86_64"),("linux","aarch64"),("macos","x86_64"),("macos","aarch64"),("windows","x86_64")];
if !SUPPORTED.contains(&(os, arch)) { eprintln!("Unsupported platform {os}/{arch}"); }

fn is_supported_platform() -> bool {
    matches!((std::env::consts::OS, std::env::consts::ARCH),
        ("linux", "x86_64") | ("linux", "aarch64") | ("macos", "aarch64") | ("macos", "x86_64") | ("windows", "x86_64"))
}

match load_baml_sys() {
    Err(BamlSysError::UnsupportedPlatform { os, arch }) => {
        eprintln!("No prebuilt BAML library for {os}/{arch}; build from source or switch platform");
    }
    Ok(sys) => { /* use sys */ }
}

When it happens

Trigger: Running on an unsupported target (e.g. freebsd, solaris, or niche arch like mips/riscv) where baml-sys has no library filename mapping or no published prebuilt library.

Common situations: Building/running in unusual containers or emulators; cross-compiling to a non-tier-1 target; using a musl/embedded target with no prebuilt native lib.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

• {0}
• BAML library not found. Searched paths
• Engine not initialized. Call create_baml_runtime first.
• Expected Collector, got
• Expected string value for tag key

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/6e1b90965daf43c1. Report an issue: GitHub.

Appendix: source

Thrown at languages/rust/baml-sys/src/error.rs:34

        path: PathBuf,
        #[source]
        source: libloading::Error,
    },

    /// Symbol not found in loaded library.
    #[error("Symbol '{symbol}' not found in BAML library: {source}")]
    SymbolNotFound {
        symbol: &'static str,
        #[source]
        source: libloading::Error,
    },

    /// Version mismatch between Rust package and loaded library.
    #[error("Version mismatch: Rust package expects {expected}, but library reports {actual}")]
    VersionMismatch { expected: String, actual: String },

    /// Platform not supported.
    #[error("Platform not supported: {os}/{arch}")]
    UnsupportedPlatform {
        os: &'static str,
        arch: &'static str,
    },

    /// Failed to determine cache directory.
    #[error("Failed to determine cache directory: {0}")]
    CacheDir(String),

    /// Download failed.
    #[error("Failed to download library: {0}")]
    DownloadFailed(String),

    /// Checksum mismatch after download.
    #[error("Checksum mismatch: expected {expected}, got {actual}")]
    ChecksumMismatch { expected: String, actual: String },

    /// IO error.

View on GitHub (pinned to bd85ce9dee)