Xcode swift 失败，退出代码为 254

Xcode swift failed with exit code 254

提问by user2280687

I am getting this compiler error in my code and I can't figure out why:

我在我的代码中遇到这个编译器错误，我不知道为什么：

<unknown>:0: error: unable to execute command: Segmentation fault: 11
<unknown>:0: error: swift frontend command failed due to signal (use -v to see invocation)
Command /Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift failed with exit code 254

The error is showing up somewhere in the following code segment:

错误显示在以下代码段中的某处：

var animalViewToSwap: AnimalView = animalViewMatrix.objectAtRow(0, andColumn: 0) as AnimalView
var currentRow = 0
var currentColumn = 0
var animalToSwapWith = true

var currentLocation = animalViewMatrix.findLocationOfObject(animalView)

currentRow = Int(currentLocation.row) - 1
currentColumn = Int(currentLocation.column) - 1

var rowDisplacement = 0
var columnDisplacement = 0

switch inDirection{

    case "left":
        columnDisplacement = withDistance * -1
        if (Int(animalViewMatrix.columns) > currentColumn + columnDisplacement)&&(currentColumn + columnDisplacement >= 0)&&(animalViewMatrix.objectAtRow(CInt(currentRow), andColumn: CInt(currentColumn + columnDisplacement)) is AnimalView)
        {
            animalToSwapWith = true;
        }
        else { animalToSwapWith = false }

    default:
        println("error")
        animalToSwapWith = false
        break
}

(I have more cases that are very similar and am leaving them out for simplicity - the bug isn't in them)

（我有更多非常相似的案例，为了简单起见，我将它们排除在外-错误不在其中）

First Error

第一个错误

One bug is in the line: animalToSwapWith = falseand if I set it to true and comment all the rest out besides the variable initialization lines the error goes away. Also if I comment all of it out but instantiate animalToSwapWith to false the error occurs even though it doesn't when it is instantiated to true.

一个错误在行中：animalToSwapWith = false如果我将其设置为 true 并注释掉变量初始化行之外的所有其他行，错误就会消失。此外，如果我将所有内容都注释掉但将 AnimalToSwapWith 实例化为 false，即使在实例化为 true 时不会发生错误，也会发生错误。

Second Error

第二个错误

There is a second error in the line:if (Int(animalViewMatrix.columns) > currentColumn + columnDisplacement)&&(currentColumn + columnDisplacement >= 0)&&(animalViewMatrix.objectAtRow(CInt(currentRow), andColumn: CInt(currentColumn + columnDisplacement)) is AnimalView)In this line all of these methods have been called earlier in the file with variables of the same types above so knowledge of the methods shouldn't matter.

行中有第二个错误：if (Int(animalViewMatrix.columns) > currentColumn + columnDisplacement)&&(currentColumn + columnDisplacement >= 0)&&(animalViewMatrix.objectAtRow(CInt(currentRow), andColumn: CInt(currentColumn + columnDisplacement)) is AnimalView)在这一行中，所有这些方法都已在文件中较早地使用上述相同类型的变量调用，因此对方法的了解无关紧要。

Conclusion

结论

Is there a reason why these two errors are occurring or is it because swift and Xcode-6 are still in beta testing and it is a bug in Xcode? Also note that when commenting the two errors out from each other one at a time the error message is the same.

发生这两个错误是否有原因，还是因为 swift 和 Xcode-6 仍处于 beta 测试阶段，这是 Xcode 中的错误？另请注意，当一次从彼此中注释掉两个错误时，错误消息是相同的。

回答by Pascal

This is a Swift compiler bug, apparently testing for two or more implicitly unwrapped optionals causes the compiler to crash under some/many circumstances. Use Apple's Bugreporterto file this issue, mark it as duplicate of rdar://17212295.

这是一个 Swift 编译器错误，显然测试两个或多个隐式解包选项会导致编译器在某些/许多情况下崩溃。使用Apple 的 Bugreporter提交此问题，将其标记为 rdar://17212295 的副本。

Example

例子

Here's a minimal example that crashes with the same error:

这是一个因相同错误而崩溃的最小示例：

let a: String!
let b: String!

if a && b {
    println("have both")
}

Compile on command line as follows and witness the same crash:

按如下方式在命令行上编译并见证相同的崩溃：

$ xcrun swift -v -g crash.swift

回答by AndrewC

I was getting the same error and I tracked it down to this: I was extending NSErrorand in the extension was defining an enum. Moving the enumdefinition out of the extension fixed the error.

我遇到了同样的错误，我将其归结为：我正在扩展NSError并且在扩展中定义了一个enum. 将enum定义移出扩展修复了错误。

extension NSError {
    enum WYBErrorCodes: Int {
        case Fatal = 1000
        case XmlParse = 1100
        case CoreData = 1200
    }

    [...]
}

回答by Vitaliy Vashchenko

I'm getting the same error when adopt NSTextViewDelegate protocol for my class. If I remove that protocol, compilation goes fine. Strange indeed.

当我的班级采用 NSTextViewDelegate 协议时，我遇到了同样的错误。如果我删除该协议，编译就可以了。确实奇怪。

回答by Byron Coetsee

For the sake of providing other possible causes and how to fix them; I was trying to set the region of a map view within in dispatch block. If I commented out the setting of the region, the error goes away.

为了提供其他可能的原因以及如何解决它们；我试图在调度块中设置地图视图的区域。如果我注释掉区域的设置，错误就会消失。

    dispatch_once(&centerMapLocation, {
//                var theSpan: MKCoordinateSpan = MKCoordinateSpanMake(0.01, 0.01)
//                var theRegion: MKCoordinateRegion = MKCoordinateRegionMake(manager.location.coordinate, theSpan)
//                self.map.setRegion(theRegion, animated: true)
                })
        }

回答by Avi

In my case, i was calling an objective-c function from swift through bridge. Signature was like -

就我而言，我通过桥从 swift 调用了一个 Objective-c 函数。签名就像 -

    - (SomeReturnType *)getSomething:(SomeOptions *)options
                          success:(void (^)(NSArray *response))success
                          failure:(void (^)(NSError *error))failure;

From swift, i was calling it as follows and getting compile error as "Xcode swift failed with exit code 254" -

从 swift 开始，我按如下方式调用它并收到编译错误“Xcode swift failed with exit code 254” -

    ObjCClass().getSomething(nil, success: {(response : Array!) in


        }, failure: {(error: NSError!)  in

        })

changing it to following worked for me -

将其更改为以下对我有用-

     ObjCClass().getSomething(nil, success: {(response : [AnyObject]!) in


        }, failure: {(error: NSError!)  in

        })

回答by PMIW

I had this error and the bug was solved in Beta 7 available online today.

我遇到了这个错误，这个错误在今天在线的 Beta 7 中得到了解决。

回答by Jesse Rosalia

I am getting this same error when I try to extend NSArrayto have a foreachmethod:

当我尝试扩展NSArray以拥有一个foreach方法时，我遇到了同样的错误：

extension NSArray {

    func foreach(f: (AnyObject -> ())) {
        for elem in self {
            f(elem)
        }
    }
}

It would appear that extending NSArray with func that takes a function argument will cause the same problems. I worked around the issue by defining a forEachInArrayfunction that takes the NSArrayas an argument:

看起来用带有函数参数的 func 扩展 NSArray 会导致同样的问题。我通过定义一个forEachInArray以NSArray为参数的函数来解决这个问题：

func forEachInArray<T>(array: NSArray, f: (AnyObject -> ())) {
    for elem in array {
        f(elem)
    }
}