Apple Mach-O Linker Error when compiling for device

Here is permanent solution.Generally overwriting project may cause this prolems.Try this method.

-UPDATE - Clang error - Mach-O Linker error

In some case error log window displaying .xctest error, to fix it

-> Select your project

-> Beside this(just before General tab) select your projectTest file from dropdown

-> There is one option (like ProjNameTests)

-> In Host Application, select your project from dropdown only if it show custom

DONE!

Old method deleted

Just ran into the same issue.

The solution (for me) = check your frameworks.

In my case I had added classes related to CoreData without "CoreData.framework". Adding it solved the MACH_O complaining.

open .xcworkspace file not .xcodeproj. I repeat open .xcworkspace file. All of your errors will go away.

I had the same problem and the issue was that I have accidently imported a .m file instead of .h in an implementation file - hope it helps