enarx: enarx run sleep test fails

Hi! I have successfully built enarx in my machine and tried a easy sleep example but got failed.

The sleep example is

use std::{thread, time};
fn main() { 
    let sleep_time = time::Duration::from_secs(5);
    thread::sleep(sleep_time);}

I compiled into wasm32-wasi format successfully, but when tried to run with enarx run --backend=sgx target/wasm32-wasi/release/sleep.wasm but got error like

thread 'main' panicked at 'assertion failed: `(left == right)`
  left: `38`,
 right: `4`', library/std/src/sys/unix/thread.rs:219:21
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at 'Unexpected AEX: GeneralProtection', /root/.cargo/registry/src/github.com-1ecc6299db9ec823/enarx-0.1.2/src/backend/sgx/thread.rs:96:18

I read source code and found that there is similar function used here but run cargo test and didn’t appear any error.

Looking forward to some reply! Thanks!