Duplicate Symbols for Architecture arm64

Question

When I try running my Xcode Project it fails with an error stating that I have duplicate symbols. I looked online where the find these duplicates but have had no luck:

Answer 1

For me it was that i imported a file as a .m not a .h by mistake

Answer 2

For me it helped to switch the "No Common Blocks" compiler setting to NO: It pretty much seems to make sense, the setting is explained here: What is GCC_NO_COMMON_BLOCKS used for?

Answer 3

For me, the issue was the style of creation of const, that worked fine until this iOS8.. i had a few lines as:

int const kView_LayoutCount = 3;

in my .h file. Six lines like resulted in 636 linker files once common blocks was set to NO. (14k+ if YES). Moved the lines to .m after stripping .h of the value declaration and compilation was good to go.

Hope this helps others!

Answer 4

On upgrading to Xcode 8, I got a message to upgrade to recommended settings. I accepted and everything was updated. I started getting compile time issue :

Duplicate symbol for XXXX Duplicate symbol for XXXX Duplicate symbol for XXXX

A total of 143 errors. Went to Target->Build settings -> No Common Blocks -> Set it to NO. This resolved the issue. The issue was that the integrated projects had code blocks in common and hence was not able to compile it. Explanation can be found here.

Answer 5

to solve this problem go to Build phases and search about duplicate file like (facebookSDK , unityads ) and delete (extension file.o) then build again .

Answer 6

If someone is experimenting this working on Flutter, don't try to pod deintegrate, pod init.

How I solved is running flutter clean, flutter run -d [iOS Device]

Hope can help somebody.