测试SwiftPlot库遇文件写入错误：failed to open file for writing

我在测试SwiftPlot库并准备接入项目时，碰到了一个无法解决的致命错误：Fatal error: Error raised at top level: failed to open file for writing。所有组件均已更新至最新版本，代码是从库的README复制后稍作修改而来，运行环境为macOS（非iOS）。

我的代码 #

import Foundation
import SwiftPlot
import AGGRenderer

let x:[Float] = [10,100,263,489]
let y:[Float] = [10,120,500,800]
let filePath = "/Users/ama25/Desktop/"
let fileName = "test"
let url = URL(string: filePath + "agg/" + fileName)

var agg_renderer: AGGRenderer = AGGRenderer()
var lineGraph = LineGraph<Float,Float>(enablePrimaryAxisGrid: true)
lineGraph.addSeries(x, y, label: "Plot 1", color: .lightBlue)
lineGraph.plotTitle.title = "SINGLE SERIES"
lineGraph.plotLabel.xLabel = "X-AXIS"
lineGraph.plotLabel.yLabel = "Y-AXIS"
lineGraph.plotLineThickness = 3.0
var output = try lineGraph.drawGraphAndOutput(fileName: fileName + "agg/" + fileName ,renderer: agg_renderer)

var data = Data(buffer: UnsafeMutableBufferPointer(start: &output, count: 1))
try data.write(to: url!)

（备注：我知道需要完善try-catch逻辑，目前仅用于测试）

错误信息 #

Swift/ErrorType.swift:200: Fatal error: Error raised at top level: failed to open file for writing

报错代码行 #

libswiftCore.dylib`:
->  0x1977e1564 <+0>: ret    

已尝试的解决步骤 #

• 关闭了应用沙箱，但问题依然存在

内容的提问来源于stack exchange，提问作者Amir Abravesh