pub fn new_unknown<T: Into<Vec<u8>>>(message: T) -> WeldError {
        WeldError {
            message: CString::new(message).unwrap(),
            code: WeldRuntimeErrno::Unknown,
        }
    }
Creates a new error with a particular message and an `Unknown` error code.

# Examples

```rust
use weld::{WeldError, WeldRuntimeErrno};

let err = WeldError::new_unknown("A new unknown error");
assert_eq!(err.code(), WeldRuntimeErrno::Unknown);
```
weld/src/lib.rs