Command failed due to signal: Abort trap: 6

Since Xcode 7 and Swift 2.0, I get the error above, like in the screenshot shown here:

![screenshot of error log][1]

I have no idea where this is coming from, cleaning and deleting derived data didn't work.

Anyone else experiencing this problem?

Project settings:

![project settings][2]

Target settings:

![target settings][3]


[1]:

[2]:

[3]:

This is normally a Swift compiler bug, and if compiler is already latest-version, we can only workaround it, for example:

## Possible workarounds
### #1

Go to project Build ***`settings -> Swift Compiler - code generation -> Optimization Level`*** ***-> For both Debug & Release select option "Fast,Single-File Optimization[-O]***


[![settings][1]][1]

>Above forces compiler to operate a little differently, which seems to prevent crash.
>
>**Note** that both "`-O`" and "`-Osize`" may fix the crash, but I prefer `-O` to match release's settings, and avoid surprises in release.

## #2

Go to "`Build settings`", and set "`Compilation mode`" to "`Whole Module`" instead of "`Incremental`".
>By default for Debug it's `Incremental`, and for Release it's `Whole Module`.

## #3

Try latest Swift compiler, which is named "toolchain" and is downloadable at:

[To see links please register here]

>**WARNING:** You can not upload such "toolchain" build to App-store .
>
>But at least you should be able to test locally.
>
>For App-store, you need to compile with Swift compiler that comes with your `Xcode` (or latest Xcode, if your current Xcode version does not compile).

### #4
Last and least (don't do this);
edit entire project's and/or pods' source-codes, and ensure guards have separate name than what they guard.
For example, replace:
```
guard let myVariableName = myVariableName else { return }
```
With something like:
```
guard let myDifferentName = myVariableName else { return }
```
>Of course, now all lines after `guard` need to use `myDifferentName`.

[1]:

My code was crashing because of nested function.
Example code is below :

Error :
```
extension UILabel {

var attributedTextTruncates: Bool {

guard numberOfLines > 0 else { return false }
return countLabelLines() > numberOfLines

func countLabelLines() -> Int {
guard let myText = attributedText else {return 0}

let labelSize = myText.boundingRect(with: CGSize(width: self.bounds.width, height: CGFloat.greatestFiniteMagnitude), options: NSStringDrawingOptions.usesLineFragmentOrigin, context: nil)
return Int(ceil(CGFloat(labelSize.height) / self.font.lineHeight))
}
}
}
```


Correct Code :

```
extension UILabel {

var attributedTextTruncates: Bool {
guard numberOfLines > 0 else { return false }
return countLabelLines() > numberOfLines
}

private func countLabelLines() -> Int {
guard let myText = attributedText else {return 0}
let labelSize = myText.boundingRect(with: CGSize(width: self.bounds.width, height: CGFloat.greatestFiniteMagnitude), options: NSStringDrawingOptions.usesLineFragmentOrigin, context: nil)
return Int(ceil(CGFloat(labelSize.height) / self.font.lineHeight))
}
}
```

This worked for me, so just give it a try. i got this error while converting the code from swift 3 to swift 4.

Simply, go to Project>Target>Build Setting and search 'Swift Compiler - Code Generation' and set Optimization level to 'No Optimization[-Onone]'.


[1]:

I made mistake of using similar constant "name" in guard statement, causing this error.

guard let model = DataModel(JSON: response),
let model = model.first else { return }

In above example, constant name "*model*" is used twice, use new constant name instead.

guard let parsedObj = DataModel(JSON: response),
let model = parsedObj.first else { return }

NOTE: Xcode compiler do not warn you on this in compilation.


Please also check this answer which help to identify cause of this error.

[To see links please register here]

My problem was with the line:

return ()

i removed the line and problem fixed!

I faced this issue when used the same constant names in a guard construction

let activityVC = ...

guard let activityVC = activityVC else { return }

But xcode didn't show me any warning for this row.

in Xcode 11 and swift 5: Go to project Build settings -> Swift Compiler - code generation -> Optimization Level -> For both Debug & Release select option "No Optimaiztion[-Onone]


![enter image description here][1]


[1]:

In my case the problem with "Abort trap: 6" was caused by setting a value of a @Published property defined in a super class, that inherits from ObservableObject (Swift 5).

Error:

class MySuperClass : ObservableObject {
@Published var myProperty : Int = 0
}

class MySubClass : MySuperClass {
func someFunc() {
myProperty = 1
}
}

Ok:

class MySuperClass : ObservableObject {
@Published var myProperty : Int = 0

func setMyProperty(value: Int) {
myProperty = value
}
}

class MySubClass : MySuperClass {
func someFunc() {
setMyProperty(value: 1)
}
}

In my case search for

[String: String]

replace with

[String: Any]