Non-Public Library SockPuppetGizmo

You have not done anything wrong. I created an empty sample project, archived it, and can confirm the SockPuppetGizmo framework is linked by default. This is either a bug with Xcode linking or with the validation in iTunes connect. I suggest we all file a radar to bring this to Apple's attention ASAP.

otool -L Products/Applications/test.app/PlugIns/test\ WatchKit\ Extension.appex/test\ WatchKit\ App.app/test\ WatchKit\ App//Yields/System/Library/PrivateFrameworks/SockPuppetGizmo.framework/SockPuppetGizmo (compatibility version 1.0.0, current version 1.0.0)/System/Library/Frameworks/UIKit.framework/UIKit (compatibility version 1.0.0, current version 3318.93.0)/System/Library/Frameworks/Foundation.framework/Foundation (compatibility version 300.0.0, current version 1142.14.0)/usr/lib/libobjc.A.dylib (compatibility version 1.0.0, current version 228.0.0)/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1214.5.1)

And

nm -u Products/Applications/test.app/PlugIns/test\ WatchKit\ Extension.appex/test\ WatchKit\ App.app/test\ WatchKit\ App//Yields__SPApplicationMaindyld_stub_binder

Edit:As many are now reporting, it's again possible to upload builds via Application Loader. Xcode 6.3.2 is still crashing on submission.

To upload via Application loader, select your archive in the Organizer, Click Export, save and .ipa file somewhere. Open Application Loader and Choose that ipa.

Seems to be working now. Submission just gives a warning but the binary goes up fine and can be submitted.

I was also facing the same issue. Here in my case just iMAC restart worked fine for me. Create a build after iMac restart and then create build and then upload, it worked perfectly for me.

Hope this helps...!!!