Segmentation fault Xcode 11

Question

Segmentation error appears while serializing 'AnyArrayBox'

2. While running pass #0 SILModuleTransform "SerializeSILPass".
3. While serializing 'AnyArrayBox' (in module 'Module') 0 swift 0x000000010d7abeb3 PrintStackTraceSignalHandler(void*) + 51 1 swift 0x000000010d7ab686 SignalHandler(int) + 358 2 libsystem_platform.dylib 0x00007fff76c31b5d _sigtramp + 29

Here is the AnyArray struct

    struct AnyArray<Element>: RandomAccessCollection {

    typealias Index = Int

    private let box: AnyArrayBase<Element>

    init<Concrete: RandomAccessCollection>(_ concrete: Concrete) where Concrete.Element == Element, Concrete.Indices == Indices {
        box = AnyArrayBox(concrete)
    }

    var startIndex: Int { return box.startIndex }
    var endIndex: Int { return box.endIndex }

    func index(after i: Int) -> Int {
        return box.index(after: i)
    }

    subscript(position: Index) -> Element {
        return box[position]
    }

}

And two others which is used in there

private class AnyArrayBase<Element>: RandomAccessCollection {

    init() {
        guard type(of: self) != AnyArrayBase.self else {
            fatalError("_AnyArrayBase<Element> is an abstract class, it can not be created; create subclass instance instead")
        }
    }

    typealias Index = Int

    var startIndex: Int { fatalError("Must override") }
    var endIndex: Int { fatalError("Must override") }

    func index(after i: Int) -> Int {
        fatalError("Must override")
    }

    subscript(position: Index) -> Element {
        fatalError("Must override")
    }

}

private final class AnyArrayBox<Concrete: RandomAccessCollection>: AnyArrayBase<Concrete.Element> where Concrete.Indices == AnyArrayBase<Concrete.Element>.Indices {

    private let concrete: Concrete

    init(_ concrete: Concrete) {
        self.concrete = concrete
    }

    override var startIndex: Int { return concrete.startIndex }
    override var endIndex: Int { return concrete.endIndex }

    override func index(after i: Int) -> Int {
        return concrete.index(after: i)
    }

    override subscript(position: Index) -> Element {
        return concrete[position]
    }

}

How can I fix it? Any recommendations?

Answer 1

this works

var dim_values : (dim1:String?,dim2:String?,dim3:String?) = (nil, nil, nil)

apparently the compiler needs an explicit initialization (to nil)