Xcode duplicated _main character

Question

I have a duplicate of the _main character.

The problem is that he says: "Duplicate the _main character in /Users/.../i386/main-B9843B6026D6EFA4.o and / Users /.../ i386 / main-B9843B6026D6EFA4.o, XXX and XXX on the in fact the same .o file. I don’t know why he thinks he duplicates the character when he is the same .o ?!

Any thanks, thanks.

Answer 1

Ah..I finds out that I have several entries in the Targets / Compiled Sources section (in the new Xcode under the section "Build Phases / Compilation Sources"). I deleted them and the problem is resolved. The multiplayer thing is probably related to Git merge.

Answer 2

It turned out that in my case, I imported the .m file instead of its .h. Solved by editing

#import "Tools.m" 

at

 #import "Tools.h" 

Answer 3

I also had this problem and it was caused by code that I imported from another project. I made grep for "int main" in my project directory:

 grep -nr "int main" . 

and found

 ./main.m:13:int main(int argc, char *argv[]) ./IMPORTED_DIR/main.m:13:int main(int argc, char *argv[]) 

IMPORTED_DIR contained an additional main.m which caused an error for me

I deleted this file from the project -> Goals -> Build phases -> Compile a list of sources, and then compiled

Answer 4

I ran into the same problem using two third-party frameworks. (AppLovin and Flurry) And I found out that by removing "all_load" from the "Other linker flags" in the build settings.

Answer 5

I had the same problem opening a project that was created with Xcode 4.0.2, with Xcode 4.1. I just decided by clicking on "Upgrade Project" (Editor / Upgrade Project). This procedure automatically deletes all duplicates.

Answer 6

If there is still a problem, try searching as follows: "int main (" and delete these files except main.m

Answer 7

I had this problem myself, but after reading the huggie solution that led me on the right path, I got a little embarrassed. So, the current solution in Xcode: Select the phases of the project, goals → builds and click "Check Settings"

Then Xcode will automatically fix its error. It is always good when tools try to stop your progress;)

Answer 8

In my case, I declared NSString in a constant file (imported by many classes), but forgot to define it as static.

eg. NSString* PARAMS = @"paramA"; should be: static NSString* PARAMS = @"paramA";

Reading the full error message allowed me to understand this: "Duplicate the PARAMS character". Do not be afraid and do not try to understand the error messages! Sometimes they can even tell you what you did wrong.

Answer 9

You can also get this for method names!

I got a duplicate symbol _runOnMainQueueWithoutDeadlocking after adding DBCamera via CocoaPods, and this is because my category in NSObject (NSObject + Tools.h) and the GPUImageOutput.m dependency file from GPUImage had a method called runOnMainQueueWithoutDeadlocking.

I was fortunate enough to remove my method from the code because I did not use it anymore or anywhere else.

I probably deserve to put a category in NSObject.

Answer 10

In my case, I imported another project in order to use the library contained inside. As a result, my project had two main.m files.

This was even more confusing since the error did not appear until a few builds later.