Function install_snarkos 

pub fn install_snarkos(
    snarkos_path: &Path,
    version: Option<&str>,
    features: &[String],
) -> Result<PathBuf>

Compiles & installs snarkOS and returns the final binary path.

• snarkos_path – the exact --snarkos value (may not exist yet)
• version – optional --version ("4.1.0" etc.)
• features – --features .. list (may be empty)