I got this error when i tried to build:
"duplicate symbol __Z8ERRCHECK11FMOD_RESULT in:
/Users/codemenmini2012-2/Library/Developer/Xcode/DerivedData/MagicSleepFullVersion-agxulkdijnxbqmbuigucmrczufyw/Build/Intermediates/MagicSleepFullVersion.build/Debug-iphonesimulator/MagicSleepFullVersion.build/Objects-normal/i386/MagicSleepViewController.o
/Users/codemenmini2012-2/Library/Developer/Xcode/DerivedData/MagicSleepFullVersion-agxulkdijnxbqmbuigucmrczufyw/Build/Intermediates/MagicSleepFullVersion.build/Debug-iphonesimulator/MagicSleepFullVersion.build/Objects-normal/i386/MagicSleepViewControllerIpad.o
ld: 1 duplicate symbol for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)"
How to solve this guys?
The error may occur when you copy and paste the contents of one file to another file with its interface name which means two classes with same interface name.
In your code you have two different files with the same Interface name.
For me this error happened because I was dumb enough to copy the whole folder of a downloaded lib to the project and there was a demo project inside it. So I had two main.m files. Hope this helps anyone!
In my case I had accidently imported .m file instead if .h file. Hope it helps someone for this kinda silly mistake.
when you create bool variables with same name in two different classes then this error comes.
"duplicate symbol __Z8ERRCHECK11FMOD_RESULT in"
so check your both classes
MagicSleepViewController.m and
MagicSleepViewControllerIpad.m.
for same bool variables.
Change the bool variable name, your problem will solve.
Looks like you have at least one (probably more) symbol (or methods, functions, etc.) that's duplicated between MagicSleepViewController.m and MagicSleepViewControllerIpad.m.
You need to either 1) change the names of one set of duplicated methods or 2) figure out a way to merge MagicSleepViewController.m & MagicSleepViewControllerIpad.m so the same code will work on both iPhones and iPads (e.g. using run time conditionals or whatever to determine what kind of device your code is currently running on).
I had #defines placed in two files that were exactly the same... DOH.
For me, a search in the finder for the named duplicates has helped.
The problem in my case was caused due to multiple references in the "Compile Sources". So I deleted one from Project->Build Phases-> Compile Sources.
Related
I am running xCode Version 10.1 (10B61), Mojave 10.14 (18A391)
Searching shows similar issue in Xcode 10 greater than a year ago, but no issues since then. The solution from last year seemed to be switching to legacy mode, but that doesn't work now. It appears the source code that is stored on my desktop is conflicting with code that is in 'DerivedData', I'm not sure why this would suddenly pop up so randomly.
I see this problem go away if I remove the last model added in Core Data. It seems to trigger when I add a relationship to another object. It's apparently random.
Any advice on how to fix this issue so I can develop?
Multiple commands produce '//Library/Developer/Xcode/DerivedData/ProjectCoreData-ehjvvgovpitmbcegzopwciptfafr/Build/Intermediates.noindex/ProjectCoreData.build/Debug-iphonesimulator/ProjectCoreData.build/Objects-normal/x86_64/Contact+CoreDataClass.o':
Target 'ProjectCoreData' (project 'ProjectCoreData') has compile command for Swift source files
Target 'ProjectCoreData' (project 'ProjectCoreData') has compile command for Swift source files
from the logs:
<unknown>:0: error: filename "Contact+CoreDataClass.swift" used twice: '/Users/<user>/Desktop/ProjectCoreData/Contact+CoreDataClass.swift' and '/Users/<user>/Library/Developer/Xcode/DerivedData/ProjectCoreData-ehjvvgovpitmbcegzopwciptfafr/Build/Intermediates.noindex/ProjectCoreData.build/Debug-iphonesimulator/ProjectCoreData.build/DerivedSources/CoreDataGenerated/ProjectCoreData/Contact+CoreDataClass.swift'
<unknown>:0: note: filenames are used to distinguish private declarations with the same name
<unknown>:0: error: filename "Contact+CoreDataProperties.swift" used twice: '/Users/<user>/Desktop/ProjectCoreData/Contact+CoreDataProperties.swift' and '/Users/<user>/Library/Developer/Xcode/DerivedData/ProjectCoreData-ehjvvgovpitmbcegzopwciptfafr/Build/Intermediates.noindex/ProjectCoreData.build/Debug-iphonesimulator/ProjectCoreData.build/DerivedSources/CoreDataGenerated/ProjectCoreData/Contact+CoreDataProperties.swift'
<unknown>:0: note: filenames are used to distinguish private declarations with the same name
Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swiftc failed with exit code 1
The reason you see this error is because Core Data creates these files by default, but you can't see them in Project Navigator. Then you create a duplicate (in Editor/Create NSManagedObject Subclass). As a result you have your error.
According to What's new in Core Data here is a picture with the solution:
For future users :
If you are using core data and If you copied entity using option+drag, then ensure that entity name and class name must be same.
None of the solutions mentioned over internet worked for me.
It happened to me after I dragged the coredata model and classes from another project, which generated duplicate files. If this is your case, go to TARGETS->Build Phases->Compile Sources, remove the duplicate files and it should be working again.
for me it was simple problem,
i had 2 source files of the exact same name,
just renamed one of them (only the swift file name) and the problem was gone
To fix this I've to open the .xcdatamodeld using finder/show package content
This image
and then repeat this operation with the .xcdatamodel.
This option
After this I've opened the file (I use Sublime) Sublime Text locate the duplicate class name Duplicate Class Name, change it, save the file and build again. Like this
I am facing a critical problem here, Xcode throws strange exception while building it's
"
duplicate symbol _selected in:
/Users/mhgaber/Library/Developer/Xcode/DerivedData/اProject-Name-aopcbghvorqhdwbyudzqsyhtekcu/Build/Intermediates/Project-Name.build/Debug-iphonesimulator/Project-Name.build/Objects-normal/i386/ClassX.o
/Users/mhgaber/Library/Developer/Xcode/DerivedData/Project-Name-aopcbghvorqhdwbyudzqsyhtekcu/Build/Intermediates/Project-Name.build/Debug-iphonesimulator/Project-Name.build/Objects-normal/i386/ClassY.o
ld: 1 duplicate symbol for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I searched a lot but I didn't find anything help me please
Look at both the files for ClassX and ClassY - What targets are they included in? Basically the _selected method is duplicated in both of them. I am going to guess this is a plain C method that happens to be named the same in both files. Try renaming _selected in one of the files.
In my case, I was declaring a const in a header file, which worked fine when building and running on the device (iPhone 5), however when attempting to simulate a 4S, all of a sudden I had some 300 "duplicate symbols".
It turns out I needed to also mark the const as static and the issue went away. Presumably it was trying to redefine the constant every time the header was referenced. The compiler isn't smart enough to just make constants static? Didn't think that would be necessary, but I guess it is.
const CGFloat kTitleAnimateDistance = 50.f;
Needed to be:
const static CGFloat kTitleAnimateDistance = 50.f;
Some time you accidentally importing the .m file instead of the .h due to which this error comes. Please check and If this is not the reason, then perform the following steps
1- Check Build phases in Target settings.
2- Go to compile source section.
3- Check if any file exists twice or once.
4- If file exist twice delete one.
5- Build again.
I was having the same problem and #dtrotzjr 's answer gave me a hint as to what could be causing it.
In my case I had a plain C void function in my framework (which xcode was complaining about as a duplicate symbol) and i needed to declare it as static void
I had the same issue. I was including a .h file with a number of const strings, methods and a struct. When I changed them all to static except the only mutable variable I wanted, it compiled just fine.
i am getting this error it si hard to explain thats why i am attaching the image
this error accure when i am adding I class Base64.h
Most likely, the file Base64.m is not properly added to your project. It doesn't get compiled so it's missing when the final image is being linked.
Make sure the file Base64.m is the same kind of project member as FirstViewController.m (similar location, similar settings etc.).
i found the solution it is amy just a trick but i create the both base64 h and m files again with different name and then use it that time it works
thank to you
From the error I am getting:
ld: duplicate symbol _main in /Users/wostler/Library/Developer/Xcode/DerivedData/UIPageViewControllerDemo-hjsgatcuhsxeokdnubifybpivzum/Build/Intermediates/UIPageViewControllerDemo.build/Debug-iphonesimulator/UIPageViewControllerDemo.build/Objects-normal/i386/fmdb.o and /Users/wostler/Library/Developer/Xcode/DerivedData/UIPageViewControllerDemo-hjsgatcuhsxeokdnubifybpivzum/Build/Intermediates/UIPageViewControllerDemo.build/Debug-iphonesimulator/UIPageViewControllerDemo.build/Objects-normal/i386/main.o for architecture i386
I can't figure out why this error is occurring. I simply changed some framework files in my project and now this error won't go away! It obviously says _main is being duplicated, but I dont know where, or why?
What is causing this?
You need to look at the main.m/.h and fmdb.m/.h files. What is most likely is that they are both importing something that defines _main, perhaps at a global level. Usually thats the sort of thing that generates this error for me.
You have two main function in your code. Do a global search for main and remove the one you don't want.
It happens when you add some other project's files to your project without remove the main function.
Sounds like you have multiple entries under Targets/Compiled Sources. Check and remove them.
I am developing an iPad app in which I have included 2 third party static libraries. The names of the object files in these 2 libraries are same. On building the app I am getting
"Apple Mach -O (id) error"
because of the same names of the object files in those 2 libraries.
How to solve this problem?
Error looks like:
ld: duplicate symbol _T_strcpy in /Users/indiait-supportservices/Desktop/untitled folder/Universal/lib/simulator/libSecurIDLib.a(mem.o) and /Users/indiait-supportservices/Library/Developer/Xcode/DerivedData/ReceiverForiOS-aqpprpcivvjjadbsutqqmtjsoczk/Build/Intermediates/ReceiverForiOS.build/Debug-iphonesimulator/myApp iPad.build/Objects-normal/i386/pdcrypte2.o for architecture i386
collect2: ld returned 1 exit status
Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/llvm-g++-4.2
failed with exit code 1.
Are you building for one architecture? If you are building for multiple architectures and use the -all_load linker flag, this breaks the linker's ability to ignore symbols that are defined for multiple architectures. As a test, try building just for armv6 and see if the error goes away.
There is a good blog post here and a similar question discussed here.
Finally, you can add the following env var to debug problems with overriding categories:
OBJC_PRINT_REPLACED_METHODS=YES. This will log which method names have been overridden by categories, just in case that is the issue.
It looks like you have two modules defining the same function, one in libSecurIDLib.a(mem.o) and pdcrypte2.o. These should be in their own namespaces (C++) or they should be prefixed so they don't collide (C).
There are work arounds if that's impossible, but it's better name things safely.