铛：错误：链接器命令失败，退出代码为1

Question

I just opened a project i havent worked for in a couple months, and just tried to compile and run it.

I immediately got:

Undefined symbols for architecture i386:
 "l_OBJC_PROTOCOL_$_VideoOverviewControllerDelegate", referenced from:
    l_OBJC_CLASS_PROTOCOLS_$_FeaturedViewController in FeaturedViewController.o
  ld: symbol(s) not found for architecture i386
 clang: error: linker command failed with exit code 1 

and no amount of cleaning helped this error. I checked the two classes referenced in the error but couldn't find any error.

Answer 1

I had this issue as well and finally found that i had implemented the same class two times. Check our class names for duplicates or duplicate .h or .m files.

Answer 2

Just be sure you didn't import a .m in your file.

#import "myFile.m"

will give you this error... just fix it with a

#import "myFile.h"

Answer 3

Probably you don't have VideoOverviewControllerDelegate (i don't know, what it is) in linked frameworks. How to add framework to project .