通道中出现CoroutineContext错误

首先，大家好，我是新来的。今天我只是和KotlinCoroutines和Channels。从官方文档中，我看到了如下通道的一个代码段：

val channel = Channel<Int>()
launch {
    // this might be heavy CPU-consuming computation or async logic, we'll just send five squares
    for (x in 1..5) channel.send(x * x)
}
// here we print five received integers:
repeat(5) { println(channel.receive()) }
println("Done!")

然后，我决定对snippetKotlin Playground进行一些修改，以使我知道有多少coroutines工作。

我的代码：

import kotlinx.coroutines.*
import kotlinx.coroutines.channels.*

fun log(msg1:String ,msg2: Int) = println("[${Thread.currentThread().name}] $msg1 $msg2")

fun main() = runBlocking {
    val channel = Channel<Int>();
    
             launch {
               for (x in 1..5) {
                channel.send(x * x) 
                log("sending",x*x)
               }
             }
    
        repeat(5){log("receiving",channel.receive())}
   
    println("Done!")
}

如预期的那样，我收到了输出：

[main @coroutine#2] sending 1
[main @coroutine#1] receiving 1
[main @coroutine#1] receiving 4
[main @coroutine#2] sending 4
[main @coroutine#2] sending 9
[main @coroutine#1] receiving 9
[main @coroutine#1] receiving 16
[main @coroutine#2] sending 16
[main @coroutine#2] sending 25
[main @coroutine#1] receiving 25
Done!

但是随后，我试图发起一个单独CoroutineScope的节目，因为我在YouTube上观看了Kotlin会议，其中“ Roman Elizarov”说明了我们可以在不同CoroutineScope的通道之间传输数据。所以，我尝试了这个：

import kotlinx.coroutines.*
import kotlinx.coroutines.channels.*

fun log(msg1:String ,msg2: Int) = println("[${Thread.currentThread().name}] $msg1 $msg2")

fun main() = runBlocking {
    val channel = Channel<Int>();
    
             launch {
               for (x in 1..5) {
                channel.send(x * x) 
                log("sending",x*x)
               }
             }
    
   
    CoroutineScope{
        launch{log("receiving",channel.receive())}
    }
   
    println("Done!")
}

运行此后，我得到一个错误 Type mismatch: inferred type is () -> Job but CoroutineContext was expected

这是我尝试纠正此错误的方法：我添加了 Dispatchers.Default

CoroutineScope{
        launch(Dispatchers.Default){log("receiving",channel.receive())}
    }
   

引发相同的错误。为朴素的代码道歉。

有人可以帮忙吗？