pub fn forkpty() -> Result<(pid_t, i32)>Expand description
forkpty(3). The child is a session leader with the slave as its
controlling terminal. The parent receives the master fd. The child may
see master_fd == -1 (Apple’s forkpty); that is returned as -1.
rustix has no forkpty. nix::pty::forkpty wraps the master in
OwnedFd, which panics on Apple’s child -1, and its Child arm
drops the master fd the caller returns as the second item.