Upon checking out the code and running `cargo test` I observe: ``` ---- too_many_submissions stdout ---- thread 'too_many_submissions' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 9, kind: Uncategorized, message: "Bad file descriptor" }', tests/driver.rs:84:56 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace ---- complete_ops_on_drop stdout ---- thread 'complete_ops_on_drop' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 9, kind: Uncategorized, message: "Bad file descriptor" }', tests/driver.rs:53:56 ```