Command failed due to signal: Abort trap: 6

In my case i had @objc protocol with optional methods and when i called its methods also in swift class i got that error, after removing the optional keyword from functions in the protocol the error was gone.

before (with error):

@objc protocol SomeDelegate:NSObjectProtocol{

optional func someDelegateMethod()
}

class MySwiftClass{
func notifyMyDelegate(){
mydelegate?.someDelegateMethod?() //this line caused the error
}
}

after:

@objc protocol SomeDelegate:NSObjectProtocol{

func someDelegateMethod()
}

class MySwiftClass{
func notifyMyDelegate(){
mydelegate?.someDelegateMethod()
}
}

I managed to get my project to build by setting the optimisation level to 'None' under the 'Swift Compiler - Code Generation' menu in the target (not the project) settings. See the screenshot below...

![enter image description here][1]


[1]:

This shouldn't be a permanent solution because it more than doubles the size of the ipa. It should be possible to switch optimisation back on when Xcode 7 comes out of beta.

This is what caused the error for me.

Before:

for (key,value) in hash{
count += value.count
}

After:

for (_,value) in hash{
count += value.count
}

It didn't like it that key was never being used anywhere. I am not sure why it should cause the build to fail though.

Ok, in my case it was because I had an enum nested in a generic class. Now, the strange thing, is that when I isolated the problem (into the BaseDao2), the compiler told me the right error, but in my real BaseDao implementation (which has more stuff), it throw "trap 6".



Type 'DaoError2' nested in generic type 'BaseDao2' is not allowed

When I had this:

class BaseDao2<T>: InjectRestSession{

enum DaoError2: ErrorType{
case FAILED_RESPONSE(String)
case INVALID_RESULT(String)
case FAIL_TO_LIST, FAIL_TO_GET
}

func get() -> T?{
return nil
}
}

Anyway, in my case, I move the DaoError out of the BaseDao<T> and everything compiled. Anyway, my feeling is that "trap 6" is what something cannot compile and the compiler got confused. Starting from a simple case, and adding back what you think might be causing the problem can be helpul to identify the problem by getting the right compile error. In other word, you have to be gentle with the swift compiler.

I am able to reproduce this simply and consistently with a brand-new project created in Xcode 7.0 beta (7A120f). Note that the problem is likely more broad than the example, but this is 100% reproducible for me by only adding a single line to a new project. This problem also appears to exclusively apply to iOS, not OS X, at least for this example. Have submitted bug report # 21376523 to Apple.

1. Create a brand-new project in Xcode 7.0 (7A120f). Type is "Game", Language is "Swift", Game Technology is "SceneKit".

2. Build and run with default settings. Project builds and runs fine in simulator (you will see the default rotating 3D spaceship model).

3. Add a single SCNVector3 property to GameViewController.swift, like this:

class GameViewController: UIViewController {
var p = SCNVector3Zero

--> Produces "Abort trap: 6". Project will no longer compile.

4. Change the constant to an empty initializer.

class GameViewController: UIViewController {
var p = SCNVector3()

--> Same problem, "Abort trap: 6"

5. Remove property, restoring to the clean project state.

--> "Abort trap: 6" is gone, project again compiles and runs.

6. Change "var" to "let".

class GameViewController: UIViewController {
let p = SCNVector3Zero

-- > Compiles and runs.

7. Change property type to SCNVector4 instead of SCNVector3.

class GameViewController: UIViewController {
var p = SCNVector4Zero

-- > Compiles and runs.


EDIT: This problem is fixed in Xcode 7.0 beta-2 (7A121l), if you are getting "Abort trap: 6" due to using a float 3 vector type (such as SCNVector3). From the release notes:

> • A compiler crash when calling C or Objective-C functions that take
> SIMD float3 parameters has been fixed. (21294916)

In my case

Error

override func observeValueForKeyPath(keyPath: (String!)?, ofObject object: (AnyObject!)?, change: ([NSObject : AnyObject]!)?, context: UnsafeMutablePointer<Void>)

Ok

override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [NSObject : AnyObject]?, context: UnsafeMutablePointer<Void>)

In my case, it was with setting a value to a parameter in a function to nil that was causing the error.

Before:

public func comparableValidator<T: Comparable>(minValue : T? = nil, maxValue : T? = nil, value: T) -> Void {
if let min = minValue {
_assertFunc(min <= value, "\(value) must be at least \(min)")
}

if let max = maxValue {
_assertFunc(max >= value, "\(value) must be at most \(max)")
}
}

After:

public func comparableValidator<T: Comparable>(minValue : T?, maxValue : T?, value: T) -> Void {
if let min = minValue {
_assertFunc(min <= value, "\(value) must be at least \(min)")
}

if let max = maxValue {
_assertFunc(max >= value, "\(value) must be at most \(max)")
}
}

I have the same problem with all Xcode 6.3 projects, I open in Xcode 7.0.
I created a new project, copied all my source files and resources and everything worked without this compiler error.
I thought this has something to do with the project settings.
I turned off the Swift compile Optimization to "none" and the Trap 6 was gone away. Perhaps there are other settings, which also generate trouble, but for me this it was.