Xcode beta 6 errors

Question

To anyone who is having similar issues in Bata 6. I solved it by deleting the content in /Users/[your username]/Library/Developer/Xcode/DerivedData as can be seen in this post Suddenly getting compiler crash "arrayForceCast" in Swift XCode beta 6

Original post:

I just installed Xcode beta 6 and am getting very unusual errors. I cannot figure out what they are.

Undefined symbols for architecture arm64:
"__TFSsoi1oUSs17_RawOptionSetType_USs21BitwiseOperationsTypeSs9Equatable__FTQ_Q__Q_",   referenced from:
  __TFC9CoolSpots29ProfileSettingsViewController13turnOnOffPushfS0_FCSo8UISwitchT_ in ProfileSettingsViewController.o
  __TFC9CoolSpots11AppDelegate11applicationfS0_FTCSo13UIApplication29didFinishLaunchingWithOptionsGSqCSo12NSDictionary__Sb in AppDelegate.o
"__TFSs15_arrayForceCastU___FGSaQ__GSaQ0__", referenced from:
  __TFC9CoolSpots8LocationcfMS0_FT6objectCSo8PFObject_S0_ in Location.o
  __TFC9CoolSpots19ShareViewController7mapViewfS0_FTGSQCSo9MKMapView_21didAddAnnotationViewsGSQGSaPSs9AnyObject____T_ in ShareViewController.o
  __TFC9CoolSpots23LoginMenuViewController7FBLoginfS0_FT_T_ in LoginMenuViewController.o
  __TFC9CoolSpots21ProfileViewController7mapViewfS0_FTGSQCSo9MKMapView_21didAddAnnotationViewsGSQGSaPSs9AnyObject____T_ in ProfileViewController.o
  __TFFC9CoolSpots21ProfileViewController11viewDidLoadFS0_FT_T_U_FTGSqGSaPSs9AnyObject___GSqCSo7NSError__T_ in ProfileViewController.o
  __TFFFC9CoolSpots21ProfileViewController11viewDidLoadFS0_FT_T_U_FTGSqGSaPSs9AnyObject___GSqCSo7NSError__T_U0_FTGSqGSaPS1____GSqS2___T_ in ProfileViewController.o
  __TFFFC9CoolSpots21ProfileViewController11viewDidLoadFS0_FT_T_U0_FTGSqCSo8PFObject_GSqCSo7NSError__T_U0_FTGSqGSaPSs9AnyObject___GSqS2___T_ in ProfileViewController.o
  ...
"__TFSs26_forceBridgeFromObjectiveCU__FTPSs9AnyObject_MQ__Q_", referenced from:
  __TFC9CoolSpots8LocationcfMS0_FT11coordinatesVSC22CLLocationCoordinate2D15relatedActivityCSo7NSArray8objectIdSS7addressSS_S0_ in Location.o
  __TFC9CoolSpots8LocationcfMS0_FT6objectCSo8PFObject_S0_ in Location.o
  __TFC9CoolSpots19ShareViewController14viewWillAppearfS0_FSbT_ in ShareViewController.o
  __TFC9CoolSpots19ShareViewController15prepareForSeguefS0_FTGSQCSo17UIStoryboardSegue_6senderGSQPSs9AnyObject___T_ in ShareViewController.o
  __TFC9CoolSpots19ShareViewController21cameraViewTookPicturefS0_FCSo7UIImageT_ in ShareViewController.o
  __TFFC9CoolSpots19ShareViewController14reverseGeocodeFS0_FGSqCSo10CLLocation_T_U_FTGSQGSaPSs9AnyObject___GSQCSo7NSError__T_ in ShareViewController.o
  __TFC9CoolSpots27ActivityTableViewController11viewDidLoadfS0_FT_T_ in ActivityTableViewController.o
  ...
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Answer 1

Yes! I too was completely confused by these errors.

Then I remembered to delete the "DerivedData" for the project (or as I did, the entire folder), found here:

~/Library/Developer/Xcode/DerivedData

(with thanks to @drmarvelous)