async await unexpected error in playground

I have this code in playground for iOS, XCode v15.3:

import Foundation
import PlaygroundSupport

func fetchWeatherHistory() async -> [Double] {
    (1...100).map { _ in Double.random(in: -10...30) }
}

func calculateAverageTemperature(for records: [Double]) async -> Double {
    let total = records.reduce(0, +)
    let average = total / Double(records.count)
    return average
}

func upload(result: Double) async -> String {
    "OKet"
}

func processWeather() async throws {
    var records = await fetchWeatherHistory()
    var average = await calculateAverageTemperature(for: records)
    var response = await upload(result: average)
    print("Server response: \(response)")
    return
}

do {
    try await processWeather()
} catch let error {
    print(error.localizedDescription)
}

I am getting this output (along with the error:

Server response: OKet
Playground execution failed:

error: execution stopped with unexpected state.
error: Execution was interrupted.
The process has been left at the point where it was interrupted, use "thread return -x" to return to the state before expression evaluation.

what is the error about, do you know? And how to fix it?

You need to tell Playgrounds that you are doing asynchronous work by setting needsIndefiniteExecution to true and calling finishExecution when you are done.

PlaygroundPage.current.needsIndefiniteExecution = true
do {
    try await processWeather()
} catch let error {
    print(error.localizedDescription)
}
PlaygroundPage.current.finishExecution()