swift failed with exit code 1 while compiling in Xcode - possibly related to Bridging-Headers

I did the same all answer says but mine issue was not resolved. I did figured out that issue was related to broken function call.

A function syntax was not wrong but its calling mechanism was wrong.

To check the exact error for this issue check following:

Select issue navigator > Click on error will show logs for error > In that select All Messages tab.

This will show all detail logs for this error.

Scroll down and You got logs like, in my case

So, by reading this I figure out that something wrong with function calling. I browse my code and resolved it, Below was correct and wrong code.

Wrong Way:

var region = MKCoordinateRegionMake(self.mapView.userLocation.coordinate, span)
// It will not shown error here but when you build project compiler shows error.

Right Way:

let region = MKCoordinateRegion(center: self.mapView.userLocation.coordinate, span: span)

I run into this last night and nothing above was solving my problem. I was about to do something very bad at my laptop when I saw, all by pure luck, that ONE (1) file was is text encoding set to UTF-16 ?!?! WTF??

This was the last file I was working on, and probably, one bad cut/paste "import" a strange character into the arena. I did a cut/paste of my code in this file to a bare bone text editor. I deleted the file, recreate it and paste back my code... and voilà! it work.

So do the above, but also check your file encoding! :-)

I had the same error message. What helped, was to set the optimization level in the swift compiler settings to None. This is not really a solution for me and I think that's one of the many bugs in the swift compiler.