Xcode 7 compile error : “Command failed due to signal: Segmentation fault: 11”

Question

Yesterday I installed the official Xcode 7 and when I tried to open one of my Swift projects, appeared an alert saying that the new Xcode version wants to update my swift co

Answer 1

For me, the problem (XCode 7.3.1) was using a += operator on a dictionary item.

for example:

func test() {
    var myDict:[String:String] = [:]
    myDict["key"] = "pig"
    myDict["key"] += "dog"

    var myArray:[String] = []
    myArray.append("pig")
    myArray[0] += "dog"
 }

This will cause a segmentation fault. Remove the += on myDict, and all is ok.

I am aware this is a bug (dictionary references are nullable) but the compiler should not crap out like this.