问题:

如果源代码中有错误，可能会弹出“SourceKitService Terminated”，代码高亮显示停止工作。它可能发生，也可能不发生，当它发生在多种不同的条件下。

我的案例:安装beta 3, OSX仅项目，一个文件检测到“半封闭范围操作符已从..对. .<”错误。弹出窗口开始出现，代码高亮显示开始失败。

解决方案:

修复Xcode检测到的错误 在Navigator中更改为不同的.swift，回到原来的 语法高亮显示重新出现，“SourceKitService Terminated”弹出

我相信我找到了一个更通用的解决方案。下面是我用来鼓励Xcode不要产生SourceKitService Terminated错误的步骤。

我的症状是:

When I would start up a new playground, I would receive an error about not being able to communicate with the playground (Error running playground: Failed prepare for communication with playground. See this image on twitter. When I would switch the playground from OS X to iOS, I would receive another error (unfortunately I did not write that one down). When I would start to type in an iOS based Swift project, attempting to use code completion/intellisense on any UIKit specific class, I would receive the SourceKitService Terminated issue in this thread.

调试过程:

我开始通过谷歌寻找SourceKitService，这得到了很少。 然后我开始监视控制台。应用程序，同时使用Xcode。这显示了几个错误: IDEPlaygroundDocument:运行游乐场时遇到错误 com.apple.CoreSimulator。CoreSimulatorService[3952]: The runtime for The selected device is not installed。

我做了什么来纠正这个问题。

如果您只是在Swift项目上下文中遇到问题，请先单独尝试一下。如果这不起作用，那么尝试下面的所有步骤。

打开项目并将目标的部署目标更改为<= 7.1。

更漫长和复杂的过程。 (前3步不一定有帮助，但我做到了，所以把它们记录在这里)

Completely delete all copies of Xcode on your system. Restart your computer. Reinstall Xcode6-beta only. Verify that you still have the issue in playground and/or projects. Open iOS Simulator. Hardware -> Device -> Manage Devices Remove all devices. Recreate all devices you want. I appended the iOS version to the end of the name, just because. Restart Xcode and the simulator. Verify that at least playgrounds no longer throw issues when switched from OS X to iOS. Open your project and change the target's deployment target to something <= 7.1.

分析

看来问题是Xcode6不能正确地找到并连接到模拟器。我不知道为什么会出现这种情况，但这让我可以继续使用Swift进行开发。这可能与模拟器二进制文件似乎移动的事实有关。

为了解决这个问题，你的Swift代码可能会有一些奇怪的问题。例如，因为您正在复制和粘贴，所以有多个iboutlet的定义。通常这只是一个无法处理的语法错误。

我的解决方案是更换模拟器。我使用的是iPhone 5S，当我切换到iPhone 5时，一切都很完美。希望未来的版本能完全修复它。

我在苹果的开发者论坛上找到了一个解决方案(需要登录，所以我也会在这里解释)。

TLDR:不要在Objective-C中导入与@interface同名的@protocol到Swift桥接头。例如，Facebook SDK有一个名为“FBGraphObject”的协议和接口。

以下是论坛帖子:

Adding Facebook SDK causes SourceKitService to crash. If you want to use beta 3 and you need Facebook SDK, one work around that I found and is working for me is refactoring Facebook SDK's @protocol FBGraphObject and renaming it to something like @protocol FBGraphObjectProtocol as an @interface FBGraphObject also exists and apparently SourceKit doesn't like it. It sure is a temporary solution just to keep you functional and you'll have to use Cocoapods or otherwise build Facebook SDK yourself rather than using the framework library. For the time being, you'll need to make sure you don't have conflicting @protocol and @interface declarations and that includes 3rd party libraries you may be using. This cost me today, hope it helps! Posted by e.parto on July 10, 2014

Xcode 6.1 Beta 3:

一旦你在一个Swift文件中定义了一个非私有类型别名(例如typealias Foo = Int)，在另一个文件中输入字母c, SourceKitService就会崩溃。

解决方案是要么放弃使用类型别名，等待下一个beta版本，要么将类型别名包装在类定义中:

public class DummyClass {
    public typealias Foo = String
}

像这样使用它:

var myVar:DummyClass.Foo?