以下代码为什么 panic ？应该怎么改？

use futures::executor::block_on;

async fn request() -> Result<(), reqwest::Error> {
    let response = reqwest::get("https://rustcc.cn").await?;  // Panic here according to backtrace
    Ok(())
}

fn main() -> Result<(), reqwest::Error> {
    block_on(request())
}