Expect in Bash Script Spawn Id exp4 not open 错误

问：

我收到一个错误，我对期望知道为什么会发生这种情况还不够了解send: Spawn id exp4 not open while executing

脚本：

#!/bin/bash

expect_ssh() {
        local ub_serv_ip="192.168.233.132"
        local ssh_username="administrator"
        local ssh_password="Password123!"
        local ub_serv_ip="127.0.0.1"
        local ssh_username="nkloney"

local script=$(expect <<EOF
        spawn ssh $ssh_username@$ub_serv_ip
        expect "*assword:"
        send "$password\r"
        expect "$ "
        send "hostname\r"
        expect "$ "
        set hostname \$expect_out(buffer)
        set hostname [string trim \$hostname]
        send "hostname -i\r"
        expect "$ "
        set ip_address \$expect_out(buffer)
        set ip_address [string trim \$ip_address]
        send "exit\r"
        expect eof
        puts \$hostname
        puts \$ip_address
EOF
)
        local hostname=$(echo "$script" | sed -n '1p')
        local ip_address=$(echo "$script" | sed -n '2p')
        export SERVER_HOSTNAME="$hostname"
        export SERVER_IP_ADDRESS="$ip_address"
}

expect_ssh

echo "Server Hostname: $SERVER_HOSTNAME"
echo "Server IP Address: $SERVER_IP_ADDRESS"

我希望它输出变量，以便我可以在 Bash 脚本中使用它们，但相反，程序需要整整一分钟才能运行，然后输出错误。