Function pio_package_parse_file 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pio_package_parse_file(
    path: *const c_char,
    errbuf: *mut c_char,
    errlen: usize,
) -> *mut PioPackage

Parse a .pio.json package file into an opaque package handle. This reads only the package envelope; case format names still enter through pio_parse_file / pio_dist_parse_file and package constructors. Returns NULL on error and writes the message into errbuf. Free the handle with pio_package_free.