objective c - duplicate symbols for architectures in Xcode

Question

Here is the error message I receive when compiling ...

Ld /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Products/Debug-iphonesimulator/MasterDetail.app/MasterDetail normal i386
    cd /Users/ilia3546/Проекты/iDecide
    setenv IPHONEOS_DEPLOYMENT_TARGET 5.0
    setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch i386 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator6.0.sdk -L/Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Products/Debug-iphonesimulator -F/Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Products/Debug-iphonesimulator -filelist /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetail.LinkFileList -Xlinker -objc_abi_version -Xlinker 2 -fobjc-link-runtime -Xlinker -no_implicit_dylibs -mios-simulator-version-min=5.0 -framework UIKit -framework Foundation -framework CoreGraphics -o /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Products/Debug-iphonesimulator/MasterDetail.app/MasterDetail

duplicate symbol _main in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/main-E0BAF2CA88EDEE32.o
duplicate symbol _OBJC_IVAR_$_MasterDetailAppDelegate._window in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailAppDelegate-C2C06F734ECE2E36.o
duplicate symbol _OBJC_IVAR_$_MasterDetailAppDelegate._navigationController in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailAppDelegate-C2C06F734ECE2E36.o
duplicate symbol _OBJC_IVAR_$_MasterDetailAppDelegate._splitViewController in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailAppDelegate-C2C06F734ECE2E36.o
duplicate symbol _OBJC_CLASS_$_MasterDetailAppDelegate in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailAppDelegate-C2C06F734ECE2E36.o
duplicate symbol _OBJC_METACLASS_$_MasterDetailAppDelegate in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailAppDelegate-C2C06F734ECE2E36.o
duplicate symbol _OBJC_IVAR_$_MasterDetailDetailViewController._detailItem in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailDetailViewController-B3C32DC7B1BE4E38.o
duplicate symbol _OBJC_IVAR_$_MasterDetailDetailViewController._TitleOfDetail in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailDetailViewController-B3C32DC7B1BE4E38.o
duplicate symbol _OBJC_IVAR_$_MasterDetailDetailViewController._detailDescriptionLabel in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailDetailViewController-B3C32DC7B1BE4E38.o
duplicate symbol _OBJC_IVAR_$_MasterDetailDetailViewController._masterPopoverController in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailDetailViewController-B3C32DC7B1BE4E38.o
duplicate symbol _OBJC_IVAR_$_MasterDetailDetailViewController.WebView in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailDetailViewController-B3C32DC7B1BE4E38.o
duplicate symbol _OBJC_CLASS_$_MasterDetailDetailViewController in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailDetailViewController-B3C32DC7B1BE4E38.o
duplicate symbol _OBJC_METACLASS_$_MasterDetailDetailViewController in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailDetailViewController-B3C32DC7B1BE4E38.o
duplicate symbol _OBJC_IVAR_$_MasterDetailMasterViewController._detailViewController in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
duplicate symbol _OBJC_IVAR_$_MasterDetailMasterViewController._Controller1 in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
duplicate symbol _OBJC_IVAR_$_MasterDetailMasterViewController.listOfDecide in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
duplicate symbol _OBJC_IVAR_$_MasterDetailMasterViewController.listOfDecideOpis in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
duplicate symbol _OBJC_IVAR_$_MasterDetailMasterViewController.listOfGraph in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
duplicate symbol _OBJC_IVAR_$_MasterDetailMasterViewController.listOfGraphOpis in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
duplicate symbol _OBJC_IVAR_$_MasterDetailMasterViewController.listOfAbout in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
duplicate symbol _OBJC_IVAR_$_MasterDetailMasterViewController.listOfAboutOpis in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
duplicate symbol _OBJC_CLASS_$_MasterDetailMasterViewController in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
duplicate symbol _OBJC_METACLASS_$_MasterDetailMasterViewController in:
    /Users/ilia3546/Library/Developer/Xcode/DerivedData/MasterDetail-fhgogwnbpzovbtaskgecptdnvgjs/Build/Intermediates/MasterDetail.build/Debug-iphonesimulator/MasterDetail.build/Objects-normal/i386/MasterDetailMasterViewController-A4C5EC1C14AE6E3A.o
ld: 23 duplicate symbols for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

appdelegate.m -

#import "MasterDetailAppDelegate.h"

#import "MasterDetailMasterViewController.h"

#import "MasterDetailDetailViewController.h"


@implementation MasterDetailAppDelegate

@synthesize window = _window;
@synthesize navigationController = _navigationController;
@synthesize splitViewController = _splitViewController;

- (void)dealloc
{
    [_window release];
    [_navigationController release];
    [_splitViewController release];
    [super dealloc];
}


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
            MasterDetailMasterViewController *masterViewController = [[[MasterDetailMasterViewController alloc] initWithNibName:@"MasterDetailMasterViewController_iPhone" bundle:nil] autorelease];
            self.navigationController = [[[UINavigationController alloc] initWithRootViewController:masterViewController] autorelease];
            self.window.rootViewController = self.navigationController; 
    } else {
        MasterDetailMasterViewController *masterViewController = [[[MasterDetailMasterViewController alloc] initWithNibName:@"MasterDetailMasterViewController_iPad" bundle:nil] autorelease];
        UINavigationController *masterNavigationController = [[[UINavigationController alloc] initWithRootViewController:masterViewController] autorelease];

        MasterDetailDetailViewController *detailViewController = [[[MasterDetailDetailViewController alloc] initWithNibName:@"MasterDetailDetailViewController_iPad" bundle:nil] autorelease];
        UINavigationController *detailNavigationController = [[[UINavigationController alloc] initWithRootViewController:detailViewController] autorelease];
        self.splitViewController = [[[UISplitViewController alloc] init] autorelease];
        self.splitViewController.delegate = detailViewController;
        self.splitViewController.viewControllers = [NSArray arrayWithObjects:masterNavigationController, detailNavigationController, nil];

        self.window.rootViewController = self.splitViewController;
    }
    [self.window makeKeyAndVisible];
    return YES;
}

- (void)applicationWillResignActive:(UIApplication *)application
{
    /*
     Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to

Answer 1

Check your import files, it may that you're importing a .m file.

#import "TimeModel.m"