1 duplicate symbol for architecture x86_64

Question

I am not sure what I have done wrong.
I moved my project folder to another folder and copied the backup folder to desktop.
I tried to open the backup project and build, I received the linker error.
So I decided to I delete my backup folder and moved back my project folder to desktop. I can't compile anymore and received the following error.

 Showing Recent Issues clang: error: linker command failed with exit code 1 (use -v to see invocation)

duplicate symbol _main in:
/Users/BRO/Library/Developer/Xcode/DerivedData/SFITNESS-flzvwdymttxhducvwvmhpuaqfzhj/Build/Intermediates.noindex/SFITNESS.build/Debug-iphonesimulator/SFITNESS.build/Objects-normal/x86_64/main-90EC778DD760FD57.o
/Users/BRO/Library/Developer/Xcode/DerivedData/SFITNESS-flzvwdymttxhducvwvmhpuaqfzhj/Build/Intermediates.noindex/SFITNESS.build/Debug-iphonesimulator/SFITNESS.build/Objects-normal/x86_64/main-F627C2B37F247040.o
ld: 1 duplicate symbol for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)  

No derived data folder

Still the same

1. I opened Derived Data folder and deleted everything in it
2. I deletes all the project in all simulator
3. I restarted xCode, Clean and build

Still the same

Added the project into GitHub

The link

Answer 1

You need to add necessary framework to your project. Check all third party party framework and search its required framework for support. For e.g. if you add google analytic then you need to add CoreData , Foundation etc framework. There is some framework is missing for which third party framework needs.

Or you can-

1. Press "Cmd + Shift + K" or shift + cmd + alt + k to clean up, and quit Xcode.

2. Delete the cache Run "rm -rf ~/Library/Developer/Xcode/DerivedData" in terminal

3. Open the project and re-build it

Linker command failed with exit code 1 - to solve this error press "Cmd + Shift + K" or shift + cmd + alt + k this will do the work for you. I also have this same issue but solved by using this line . Hope this will solve your problem.

OUTPUT OF YOUR PROJECT -

Answer 2

duplicate symbol _main

You have two main.m files and the function main() is in conflict.

Just delete the main.m under CERangeSlider and it should work.