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

I have an Obj-C Project I'm trying to migrate to Swift. I did succeed with various classes but recently ran into an issue I can't seem to make sense of. When I try to compile my current code base I get the following (SUPER UNHELPFUL ERROR MESSAGE)

Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swiftc failed with exit code 1

My only assumption is its somehow related to my bridging-headers but Xcode isn't giving me enough information to figure out if this is actually true.

I'm using Cocoapods to add the CorePlot to my project. I'm trying to migrate the following class to Swift:

Obj-C Class (ScatterPlotContainer.h)

#import <Foundation/Foundation.h>

@class CPTScatterPlot;

@interface ScatterPlotContainer : NSObject
@property (nonatomic, strong) CPTScatterPlot *ahrsAlt;
@property (nonatomic, strong) CPTScatterPlot *calibration;
@property (nonatomic, strong) CPTScatterPlot *coreAlt;
@property (nonatomic, strong) CPTScatterPlot *pitch;
@property (nonatomic, strong) CPTScatterPlot *roll;
@property (nonatomic, strong) CPTScatterPlot *slip;
@end

Obj-c Class (ScatterPlotContainer.m)

#import <CorePlot/CPTScatterPlot.h>
#import "ScatterPlotContainer.h"


@implementation ScatterPlotContainer {

}
@end

Swift Conversion

import Foundation

 class ScatterPlotContainer : NSObject {
    public var ahrsAlt : CPTScatterPlot;
    public var calibration : CPTScatterPlot;
    public var coreAlt : CPTScatterPlot;
    public var pitch : CPTScatterPlot;
    public var roll : CPTScatterPlot;
    public var slip : CPTScatterPlot;
}

My bridging headers file

#import <CorePlot/CPTScatterPlot.h>

What I've tried thus far

When I comment out the #import <CorePlot/CPTScatterPlot.h> from the Bridging headers file - I get an error in swift because it doesn't know what CPTScatterPlot is

I've also tried #import <CPTScatterPlot.h> which didn't work either.

Thoughts

So the only thing I can think of is perhaps because I'm using a cocoa pod there is some sort of module name I need to add. The error message really isn't that useful. Does anybody have a suggestion about some blaring error I've made or how to get a more descriptive error message to figure out what is going on?

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.

Another solution for this issues is to check that you don't have 2 or more files with the same file names. It solved the problem for me.

Thank you @Kampai for the advice on going through the error log message. I read through, and some files were missing:

<unknown>:0: error: no such file or directory:  

Somehow, some files were removed during a pull from GitHub. The files are in the directory, but not in the Xcode project.

Right click on a folder and click 'Add files to ...' to manually add missing files to Xcode. That fixed the problem for me.

This happened to me several times already, but now I know how to fix it \o/