Xcode 8 SiriKit Extension - Could not attach to pid

Question

Almost every time I try to run my SiriKit Extension, I get "Sorry, you'll need to continue in the app" along with "Could not attach to pid : '####'" on Xcode. I have Siri capability enabled. Weirdly, 1 out of 10 times when I clean and rebuild, the extension works. Does anyone know how to deal with this?

Edit: In console.app I'm getting this:

Aug 15 11:43:43 iPhone assistantd(PlugInKit)[12442] <Info>: preparing plug-in <private>(<private>)
Aug 15 11:43:43 iPhone assistantd(PlugInKit)[12442] <Notice>: connection to plug-in <private>(0DDA43D4-A588-4478-8405-C219EAA7F591) lost
Aug 15 11:43:43 iPhone assistantd(PlugInKit)[12442] <Error>: Hub connection error Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.appID.SiriKitExtension" UserInfo={NSDebugDescription=connection to service named com.appID.SiriKitExtension}
Aug 15 11:43:43 iPhone assistantd(PlugInKit)[12442] <Info>: beginUsing of 0DDA43D4-A588-4478-8405-C219EAA7F591 concludes with error=Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.appID.SiriKitExtension" UserInfo={NSDebugDescription=connection to service named com.appID.SiriKitExtension}
Aug 15 11:43:43 iPhone assistantd(Foundation)[12442] <Notice>: PlugInKit error in beginUsing:
Aug 15 11:43:43 iPhone assistantd[12442] <Error>: __52-[ADExtensionService handleCommand:forDomain:reply:]_block_invoke_2.154 Error with extension request Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.appID.SiriKitExtension" UserInfo={NSDebugDescription=connection to service named com.appID.SiriKitExtension}
Aug 15 11:43:43 iPhone assistantd(Foundation)[12442] <Notice>: killing invalid plugIn
Aug 15 11:43:43 iPhone assistantd[12442] <Error>: -[ADCommandCenter _handleServiceReply:error:forCommand:] Handling service error Error Domain=kAFAssistantErrorDomain Code=1301 "(null)" UserInfo={NSUnderlyingError=0x1005d1eb0 {Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.appID.SiriKitExtension" UserInfo={NSDebugDescription=connection to service named com.appID.SiriKitExtension}}} for command <private>

Answer 1

Fixed the problem after weeks of debugging.

My problem was that SiriKit was running on armv7 architecture. Changing it to arm64 or the default setting of armv7 + arm64 will fix this problem.

I hope this helps someone!