Command failed due to signal: Abort trap: 6

Question

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

Answer 1

I got this message when using do-try-catch in a Failable initializer:

public init?() {
    do {
        ...
        super.init(superParam: try getParamForSuper())
        ...
    } catch {
        ...
    }
}

The compilation succeeded when moving the try call to it's own local variable:

public init?() {
    do {
        ...
        let superParam = try getParamForSuper()
        super.init(superParam: superParam)
        ...
    } catch {
        ...
    }
}

Answer 2

My case, Swift 5.1, Xcode 10.3 (10G8)

Code was crashing Swift when a nested function was using the argument of an outer function as a default parameter.

e.g.

func foo(duration: TimeInterval) {
    func bar(duration: TimeInterval = duration) {
    }
}

I hope this helps.

Answer 3

To me what caused this error was:

I created a file to create extensions on UIView. Inside this file, I created a private protocol named Foo.

Then I made:

extension UIView: Foo

Removing the private from the protocol made the error go away.

I guess this is probably a bug. The compiler should warn us about the issue. The same way it warns us we can't add private conformances to types it should tell us that conformance should be using a "public/internal" protocol.

Answer 4

I didn't try other solutions. I got this problem for this setup:

func speacialAdd(_ num1: Int, to num2: Int){
    func specialMultiply(_ digit1: Int, with digit2: Int = num2){ // SOURCE OF PROBLEM
        print(digit2)
        print(digit1)
    }

    specialMultiply(5)
}

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        print(speacialAdd(5, to: 6))
    }
}

This line is the source of problem. Defaulting it to a argument seems to not work for a nested function

func specialMultiply(_ digit1: Int, with digit2: Int = num2) // ERROR

Solutions are:

func specialMultiply(_ digit1: Int, with digit2: Int) // OK
func specialMultiply(_ digit1: Int, with digit2: Int = 6) // OK

---

FWIW I actually first wrote this in playground and got a different error:

Playground execution failed:

error: Couldn't lookup symbols:
__T013__lldb_expr_111speacialAddySi_Si2totF4num2L_Sifau

Answer 5

In my case,

The compiler would give me the message:

Incorrect number of arguments passed to called function!
%4 = call %swift.type* @_T015SimplifiedCoder6StructVMa() #1, !dbg !3112
<unknown>:0: error: fatal error encountered during compilation; please
file a bug report with your project and the crash log
<unknown>:0: note: Broken function found, compilation aborted!

but I realized that I missed a default generic parameter:

class Class<K> {
    init<T: Protocol>(_ value: T) where T.Key == K {}
}

protocol Protocol {
    associatedtype Key
    static func getClass<NewKey>(_: NewKey.Type) -> Class<NewKey>
}

struct Struct<K>: Protocol {

    typealias Key = K

    static func getClass<NewKey>(_: NewKey.Type) -> Class<NewKey> {
        let _self = Struct<NewKey>()
        return Class(_self)
    }
}

protocol CanGetClass {
    associatedtype StructType: Protocol
}

extension CanGetClass {
    func getClass<Key>(_: Key.Type) -> Class<Key> {
        return StructType.getClass(Key.self)
    }
}

struct R: CanGetClass {
    typealias StructType = Struct
}

changed:

typealias StructType = Struct

to:

typealias StructType = Struct<Int>

the extension of CanGetClass tried to call getClass on an incomplete type.

Answer 6

This issue is still present in Xcode 10.2.1. After cleaning the build folder, the error went away.