Procspawn failing in tests

Hello,
In order to fix this issue https://github.com/servo/ipc-channel/issues/263, I wanted to create a test with two processes. procspawn would be really helpful there, thus I wanted to use it.

For some reason, when I try to start a process sending a rx channel, this fails.
This is a minimal failing example:

procspawn::enable_test_support!();
#[test]
fn test_basic() {
    let (tx, rx) = ipc::channel().unwrap();
    let handle = procspawn::spawn((rx), |(rx)| {
        println!("Hello world!");
        let receved = rx.recv().expect("Something went wrong.");
        receved
    });
    tx.send(3).unwrap();
    let value = handle.join().unwrap();
    assert_eq!(value, 3);
}

The error:

thread 'test_basic' panicked at 'called `Result::unwrap()` on an `Err` value: SpawnError { kind: IpcChannelClosed(Custom { kind: ConnectionReset, error: "remote closed" }) }', tests/fd_passing.rs:18:17

Version:

rustc --version
rustc 1.43.1 (8d69840ab 2020-05-04)

procspawn = {version = "~0.9" , features= ["test-support"]}

If instead of passing channels I use a number for example, everything works as expected.
Any idea on what would be the issue? Thanks!

Start with the minimal example and the failure at tests/fd_passing.rs:18:17, then inspect procspawn::enable_test_support! and the procspawn::spawn path for receiving an IPC channel. Compare this with the working case that passes a number. Done means the two-process test can pass the channel, send 3, join successfully, and return 3.