Can't build GCM with Protobuf in Xcode - objective-c

Question

Recently I've decided to integrate GCM to my project that already uses Google Protocol Buffers. Everything worked fine, sample was OK. But when I've tried to integrate GCM via CocoaPods to my project - I started receiving build errors:
Undefined symbols for architecture x86_64:
"_GSDK_PBLogicalRightShift32", referenced from:
_SerializedSize in libGcmLib.a(GCMSecureSocket.o)
"_OBJC_CLASS_$_GSDK_PBCodedOutputStream", referenced from:
objc-class-ref in libGcmLib.a(GCMSecureSocket.o)
"_OBJC_CLASS_$_GSDK_PBDescriptor", referenced from:
objc-class-ref in libGcmLib.a(GtalkCore.pb.o)
objc-class-ref in libGcmLib.a(GtalkExtensions.pb.o)
"_OBJC_CLASS_$_GSDK_PBGeneratedMessage", referenced from:
_OBJC_CLASS_$_GtalkHeartbeatPing in libGcmLib.a(GtalkCore.pb.o)
_OBJC_CLASS_$_GtalkHeartbeatAck in libGcmLib.a(GtalkCore.pb.o)
_OBJC_CLASS_$_GtalkErrorInfo in libGcmLib.a(GtalkCore.pb.o)
_OBJC_CLASS_$_GtalkSetting in libGcmLib.a(GtalkCore.pb.o)
_OBJC_CLASS_$_GtalkLoginRequest in libGcmLib.a(GtalkCore.pb.o)
_OBJC_CLASS_$_GtalkLoginResponse in libGcmLib.a(GtalkCore.pb.o)
_OBJC_CLASS_$_GtalkClose in libGcmLib.a(GtalkCore.pb.o)
...
"_OBJC_CLASS_$_GSDK_PBRootObject", referenced from:
_OBJC_CLASS_$_GtalkGtalkCoreRoot in libGcmLib.a(GtalkCore.pb.o)
_OBJC_CLASS_$_GtalkGtalkExtensionsRoot in libGcmLib.a(GtalkExtensions.pb.o)
"_OBJC_METACLASS_$_GSDK_PBGeneratedMessage", referenced from:
_OBJC_METACLASS_$_GtalkHeartbeatPing in libGcmLib.a(GtalkCore.pb.o)
_OBJC_METACLASS_$_GtalkHeartbeatAck in libGcmLib.a(GtalkCore.pb.o)
_OBJC_METACLASS_$_GtalkErrorInfo in libGcmLib.a(GtalkCore.pb.o)
_OBJC_METACLASS_$_GtalkSetting in libGcmLib.a(GtalkCore.pb.o)
_OBJC_METACLASS_$_GtalkLoginRequest in libGcmLib.a(GtalkCore.pb.o)
_OBJC_METACLASS_$_GtalkLoginResponse in libGcmLib.a(GtalkCore.pb.o)
_OBJC_METACLASS_$_GtalkClose in libGcmLib.a(GtalkCore.pb.o)
...
"_OBJC_METACLASS_$_GSDK_PBRootObject", referenced from:
_OBJC_METACLASS_$_GtalkGtalkCoreRoot in libGcmLib.a(GtalkCore.pb.o)
_OBJC_METACLASS_$_GtalkGtalkExtensionsRoot in libGcmLib.a(GtalkExtensions.pb.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I've assumed that this is because GCM library has ProtocolBuffers in it and it is conflicting with my Protobuf sources that I've got from here:
https://github.com/google/protobuf/tree/master/objectivec
I've also tried to build for the device and as a result receive similar error - with armv7 instead of x86_64. Also I must say, that sample project works fine, so I think that Protobuf is that main issue here.
Still, I have no idea how this could be resolved. Any thoughts?

Answer 1

Check if the architecture of libGcmLib.a and your target build architecture are the same.
You can check the architecture of .a file with command
otool -hv libGcmLib.a
Apprarently following objects are not built against x86_64 architecture.
GCMSecureSocket.o
GtalkCore.pb.o
...
How do you build libGcmLib.a static lib ? Review it.