我发现从终端删除派生数据可以解决这个问题，直到下一次崩溃。:年代

它位于:/Users/{用户名}/Library/Developer/Xcode/DerivedData/{项目名}-{随机字符序列}

我希望这能有所帮助。

在我的情况下，我已经导入桥接头丢失的文件。在我删除错误导入后，错误通知消失了。

我的答案(Xcode6-Beta7)是简单地删除派生数据文件夹。

首选项>位置>衍生数据>单击箭头打开Finder >垃圾。

很明显，这种崩溃的发生有很多原因。

你的项目叫Swift吗?看到这个消息，构建也会失败(<unknown>:0: error:模块名“Swift”是为标准库保留的)。尝试使用其他项目名称，例如SwiftTest。它会起作用的。

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

在xcode中，转到你的菜单栏>>窗口>> devices (shift+cmd+2)，一个新的窗口将弹出，并在左下角，添加一个新的模拟器，特别是一个运行在iOS 8.0上的现有列表 编辑:你可能需要重新启动xcode

具有:http://www.reddit.com/r/swift/comments/2bznfo/error_running_playground_unable_to_find_suitable/