在定位x64平台时，IronPython双重拼接不正确

Question

当我使用自定义AppDomain和PermissionSet时，我在IronPython中遇到了一个奇怪的问题。出于某种原因，当PermissionSet不是Unrestricted并且我构建目标x64平台时，将双精度转换为浮点数无法正常工作。当我构建目标x86平台或使用PermissionState.Unrestricted时，问题就消失了。我也尝试从PermissionState.None开始，并将列出here的每个权限添加为Unrestricted，但它仍然无法正常工作。我正在使用IronPython 2.7.4 for .NET 4.0。下面是一个简单的程序，可以重现问题。知道这里发生了什么吗？

using IronPython.Hosting;
using System;
using System.Security;
using System.Security.Permissions;

namespace TestApp
{
    public class Program
    {
        private const string Test = @"
from System import Console
num = float(10.0)
Console.WriteLine(num)
";

        public static void Main(string[] args)
        {
            // Prints 10 always
            var permissionSet1 = new PermissionSet(PermissionState.Unrestricted);
            RunTest(permissionSet1);

            // Prints 0 on x64 builds
            var permissionSet2 = new PermissionSet(PermissionState.None);
            permissionSet2.AddPermission(new SecurityPermission(SecurityPermissionFlag.Execution));
            RunTest(permissionSet2);

            Console.ReadKey();
        }

        private static void RunTest(PermissionSet permissionSet)
        {
            var appDomainSetup = new AppDomainSetup { ApplicationBase = "." };
            var evidence = AppDomain.CurrentDomain.Evidence;
            var appDomain = AppDomain.CreateDomain("ScriptingSandbox", evidence, appDomainSetup, permissionSet);
            var scriptEngine = Python.CreateEngine(appDomain);
            var scriptSource = scriptEngine.CreateScriptSourceFromString(Test);
            scriptSource.Execute();
        }
    }
}