Xcode 12，React Native应用程序，不再显示模拟器

问题描述

我正在开发一个React Native应用程序（已经被弹出），最近我升级到了Xcode 12，但是从那时起，我的模拟器就从我的不同方案列表中消失了：

但是当我运行xcrun simctl list时，我可以在列表中看到模拟器和运行时：

== Device Types ==
iPhone 4s (com.apple.CoreSimulator.SimDeviceType.iPhone-4s)
iPhone 5 (com.apple.CoreSimulator.SimDeviceType.iPhone-5)
iPhone 5s (com.apple.CoreSimulator.SimDeviceType.iPhone-5s)
iPhone 6 Plus (com.apple.CoreSimulator.SimDeviceType.iPhone-6-Plus)
iPhone 6 (com.apple.CoreSimulator.SimDeviceType.iPhone-6)
iPhone 6s (com.apple.CoreSimulator.SimDeviceType.iPhone-6s)
iPhone 6s Plus (com.apple.CoreSimulator.SimDeviceType.iPhone-6s-Plus)
iPhone SE (1st generation) (com.apple.CoreSimulator.SimDeviceType.iPhone-SE)
iPhone 7 (com.apple.CoreSimulator.SimDeviceType.iPhone-7)
iPhone 7 Plus (com.apple.CoreSimulator.SimDeviceType.iPhone-7-Plus)
iPhone 8 (com.apple.CoreSimulator.SimDeviceType.iPhone-8)
iPhone 8 Plus (com.apple.CoreSimulator.SimDeviceType.iPhone-8-Plus)
iPhone X (com.apple.CoreSimulator.SimDeviceType.iPhone-X)
iPhone Xs (com.apple.CoreSimulator.SimDeviceType.iPhone-XS)
iPhone Xs Max (com.apple.CoreSimulator.SimDeviceType.iPhone-XS-Max)
iPhone Xʀ (com.apple.CoreSimulator.SimDeviceType.iPhone-XR)
iPhone 11 (com.apple.CoreSimulator.SimDeviceType.iPhone-11)
iPhone 11 Pro (com.apple.CoreSimulator.SimDeviceType.iPhone-11-Pro)
iPhone 11 Pro Max (com.apple.CoreSimulator.SimDeviceType.iPhone-11-Pro-Max)
iPhone SE (2nd generation) (com.apple.CoreSimulator.SimDeviceType.iPhone-SE--2nd-generation-)
iPod touch (7th generation) (com.apple.CoreSimulator.SimDeviceType.iPod-touch--7th-generation-)
iPad 2 (com.apple.CoreSimulator.SimDeviceType.iPad-2)
iPad Retina (com.apple.CoreSimulator.SimDeviceType.iPad-Retina)
iPad Air (com.apple.CoreSimulator.SimDeviceType.iPad-Air)
iPad mini 2 (com.apple.CoreSimulator.SimDeviceType.iPad-mini-2)
iPad mini 3 (com.apple.CoreSimulator.SimDeviceType.iPad-mini-3)
iPad mini 4 (com.apple.CoreSimulator.SimDeviceType.iPad-mini-4)
iPad Air 2 (com.apple.CoreSimulator.SimDeviceType.iPad-Air-2)
iPad Pro (9.7-inch) (com.apple.CoreSimulator.SimDeviceType.iPad-Pro--9-7-inch-)
iPad Pro (12.9-inch) (1st generation) (com.apple.CoreSimulator.SimDeviceType.iPad-Pro)
iPad (5th generation) (com.apple.CoreSimulator.SimDeviceType.iPad--5th-generation-)
iPad Pro (12.9-inch) (2nd generation) (com.apple.CoreSimulator.SimDeviceType.iPad-Pro--12-9-inch---2nd-generation-)
iPad Pro (10.5-inch) (com.apple.CoreSimulator.SimDeviceType.iPad-Pro--10-5-inch-)
iPad (6th generation) (com.apple.CoreSimulator.SimDeviceType.iPad--6th-generation-)
iPad (7th generation) (com.apple.CoreSimulator.SimDeviceType.iPad--7th-generation-)
iPad Pro (11-inch) (1st generation) (com.apple.CoreSimulator.SimDeviceType.iPad-Pro--11-inch-)
iPad Pro (12.9-inch) (3rd generation) (com.apple.CoreSimulator.SimDeviceType.iPad-Pro--12-9-inch---3rd-generation-)
iPad Pro (11-inch) (2nd generation) (com.apple.CoreSimulator.SimDeviceType.iPad-Pro--11-inch---2nd-generation-)
iPad Pro (12.9-inch) (4th generation) (com.apple.CoreSimulator.SimDeviceType.iPad-Pro--12-9-inch---4th-generation-)
iPad mini (5th generation) (com.apple.CoreSimulator.SimDeviceType.iPad-mini--5th-generation-)
iPad Air (3rd generation) (com.apple.CoreSimulator.SimDeviceType.iPad-Air--3rd-generation-)
iPad (8th generation) (com.apple.CoreSimulator.SimDeviceType.iPad--8th-generation-)
iPad Air (4th generation) (com.apple.CoreSimulator.SimDeviceType.iPad-Air--4th-generation-)
Apple TV (com.apple.CoreSimulator.SimDeviceType.Apple-TV-1080p)
Apple TV 4K (com.apple.CoreSimulator.SimDeviceType.Apple-TV-4K-4K)
Apple TV 4K (at 1080p) (com.apple.CoreSimulator.SimDeviceType.Apple-TV-4K-1080p)
Apple Watch - 38mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-38mm)
Apple Watch - 42mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-42mm)
Apple Watch Series 2 - 38mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-2-38mm)
Apple Watch Series 2 - 42mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-2-42mm)
Apple Watch Series 3 - 38mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-3-38mm)
Apple Watch Series 3 - 42mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-3-42mm)
Apple Watch Series 4 - 40mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-4-40mm)
Apple Watch Series 4 - 44mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-4-44mm)
Apple Watch Series 5 - 40mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-5-40mm)
Apple Watch Series 5 - 44mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-5-44mm)
Apple Watch SE - 40mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-SE-40mm)
Apple Watch SE - 44mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-SE-44mm)
Apple Watch Series 6 - 40mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-6-40mm)
Apple Watch Series 6 - 44mm (com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-6-44mm)
== Runtimes ==
iOS 14.0 (14.0 - 18A372) - com.apple.CoreSimulator.SimRuntime.iOS-14-0
tvOS 14.0 (14.0 - 18J383) - com.apple.CoreSimulator.SimRuntime.tvOS-14-0
watchOS 7.0 (7.0 - 18R382) - com.apple.CoreSimulator.SimRuntime.watchOS-7-0

如果我在Xcode中创建一个新项目，则可以看到模拟器。

我试图将构建设置，常规设置和签名设置作为方案设置与另一个可以看到模拟器的项目进行比较，但是找不到任何相关差异。

我可以在设备上构建（所以我想项目设置不会太糟糕）。

我还尝试了Xcode（12.6）的最新测试版，结果相同。 我做了几次全新的卸载，还重新安装了XCode 12。

我尝试为iOS 12.0和12.4安装模拟器，将应用程序的目标设置为12.0、12.4、14.0。所有模拟器都已安装并可用于其他项目，但未在该项目中显示。

这似乎是一个设置问题，但我无法弄清缺少/设置不正确的地方。

解决方法

我在使用Xcode 11.7的现有项目中遇到了同样的问题。升级到Xcode 12之后，我无法选择模拟器。创建新项目时，我可以在模拟器中运行它，因此我仔细比较了两个项目之间的构建设置。

我注意到新的（工作中）项目中的Architectures值设置为$（ARCHS_STANDARD），而我现有项目中的Architectures值设置为arm64。将值更改为$（ARCHS_STANDARD）可以解决此问题。

在Xcode中选择项目后，选择构建目标，然后选择“构建设置”选项卡。确保选择“全部”而不是“基本”，然后选择“体系结构/体系结构”。单击其值并将其设置为$（ARCHS_STANDARD）。您可能会发现可以选择一个称为“标准体系结构”的值，该值还将其设置为所需值。

您现在应该可以从窗口顶部的模式选择器中的常规模拟器列表中进行选择。

,

就我而言，似乎Xcode项目中的体系结构设置在Xcode 12 UI中不再可见。

> grep -r VALID_ARCHS ios
ios/MyProject.xcodeproj/project.pbxproj:  VALID_ARCHS = "arm64 arm64e";
ios/MyProject.xcodeproj/project.pbxproj:  VALID_ARCHS = "arm64 arm64e";

使用vim删除这些文件，然后在Xcode中重新打开项目，以使模拟器重新开始显示。

,

对我来说，问题是我将iOS Deployment Target to 13.5设置为最大iOS version was 13.4-我认为我不小心是通过xcode GUI中的代码来做到这一点的

打开YourProj.xcworkspace =>，然后在“项目”标签下选择您的项目名称，然后更改iOS Deployment Target以匹配您的模拟器已安装的项目