[UNSOLVED] XCode Error with Google Cardboard

Code (CSharp):

1. Undefined symbols for architecture armv7:
2.   "gvr::CreateMainApp__EXPECTED_EXACTLY_ONE_VR_MAIN_APP_STATEMENT__(std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > const&)", referenced from:
3.       l001 in libvrunity.a(vr_ios.o)
4. ld: symbol(s) not found for architecture armv7
5. clang: error: linker command failed with exit code 1 (use -v to see invocation)

I just have no idea what to do because this is XCode

Any help is appreciated

 

Forgot to add that I'm using Xcode 7.2 and unity 5.2.1

 

bump

 

Do you have the -ObjC flag turned on in the Xcode project? If so, try removing it.

 

I have tried, Same Error

 

bump

 

Bump?????

 

Ok, so the problem is that something is pulling in vr_ios.o during the Xcode project's link phase. That's where this undefined symbol (CreateMainApp__EXPECTED_EXACTLY_ONE_VR_MAIN_APP_STATEMENT__) lives -- it's not used in Cardboard but is in other programs that use this library. The most common reason vr_ios gets pulled in is if somehow the -ObjC flag is added to the linker flags, because there is some ObjectiveC "category" in this file. Some other Unity plugins turn this flag on, so if you are using any other plugins, can you mention them? If none of those are the case, then I'm really not sure what is causing this link dependency. It's already on the internal Google bug list so that a "true" fix can be found.

 

Not using any plugins except for cardboard itself... I disabled the -ObjC flag, enabled it. Bitcode and what not also... I hope someone here can find a fix or they update google cardboard itself soon D:

 

bump

 

@dolims
Anyone else?
Unity Staff?
Bump.

 

Yeah, stumped so far. Any way you can share a cut-down project that exhibits the issue?

 

It's a flight sim game. There are no plugins only c# scripts

 

@dolims

 

Bump......
Can any unity support help me?

 

Doubt they can help. This symbol is specific to the Cardboard SDK implementation internals. Just for sanity, do you get this error when building the SDK's demo project?

 

'Scuse me, Anyone find a fix yet?

 

Bump!

 

Bump, bump, bump!!!!!!!!!!!

 

Yes, the official page for issues with the Cardboard plugin is https://github.com/googlesamples/cardboard-unity

Although, I'm the primary person who manages that page anyway...

All I can say is 1) the underlying issue is being tracked as a bug for an upcoming release, and 2) I have no idea how you are triggering it with your current project. Do you have a small (cut down) version of the project which has this build error that you would be willing to share?

 

@dolims
I'll zip the entire project folder to you

 

@dolims
here:
https://www.dropbox.com/s/krk6urvww0gq0b5/Fly.zip?dl=0

 

Got it. OK, I found that there's another flag in Xcode that does similar things as -ObjC: -all_load
That one is also in the linker flags of your Xcode project. Removing both -ObjC and -all_load, I was able to build and run your app.
Now, for some reason, each time I build from Unity, those flags are reappearing in the Xcode project. Maybe it's an Xcode 7+ thing. Anyway, once this "undefined symbol" bug in the actual Cardboard library is fixed, you won't have to worry about these flags anymore. So for now, just remove them.

As you'll see though, once you get past this error you will run into another one. For some reason the eyes are black, but the surrounding vignette shows the view. I've seen this error before and I was able to fix it in your project. Just do this: Delete the Cardboard object and replace the Main Camera with a CardboardMain prefab. That seems to fix the issue in this project.

 

@dolims
Thank you so so much, I got it to work!
If I have any issues later I'll PM you.

 

I get the same error. But I want to use other the plugin which required -ObjC flag. Anybody know how linking Cardboard with -ObjC flag?

 

At the moment, there is no easy workaround. It will be fixed in an upcoming release.

 

dolims, thx for advice. But know you how soon will release with fixed this issue?

 

Here is a solution until they fix it in new release.
Including this code in a C++ file:

Code (CSharp):

1. #include <vector>
2. namespace gvr {
3. class VrApp;
4. VrApp* CreateMainApp__EXPECTED_EXACTLY_ONE_VR_MAIN_APP_STATEMENT__(const std::vector<std::string>&) { return nullptr; }
5. }

Issue on github: https://github.com/googlesamples/cardboard-unity/issues/130

 

This is fixed in v0.6 of the Cardboard SDK.

 

@dolims
Good to know