`Calendar` API崩溃了Swift Playground

import Foundation

// let c1 = Calendar.shared
let c2 = Calendar(identifier: .gregorian)

我在两者之间进行了切换,在运行游乐场时都会出现同样的错误：

error: Execution was interrupted, reason: EXC_BAD_ACCESS
(code=EXC_I386_GPFLT).

我正在运行Xcode 9 beta 2

就像Hamish所说,测试版软件是错误的.