Xcode 7.3 wont attach to simulator to debug

Question

So I upgraded to Xcode 7.3.1 and now my Xcode will build, and deploy my apps (yes every app, even a brand new blank one) to the simulator but the app never launches on the simulator and the debugger never attaches, Xcode just hangs and has to be force quit. I've completely wiped out Xcode and all simulators and re-installed to no avail. I've scoured Stack Overflow and Google trying every piece of advice and still no luck. Anyone anywhere have any idea how to solve this issue? If I downgrade to 7.2.1 I'm able to debug in the simulator just fine.

Let me know if you need more information.

My Apps run just fine on the simulator, and if I try to attach the debugger to a running app it wont and Xcode hangs in the attempt, when attempting to attach this way at least Xcode doesn't have to be force quit.

FYI, I can debug on a device this is only a simulator issue.

Answer 1

I had this same issue, and tried fixing my projects and reinstalled Xcode twice before I was able to get Simulator to crash and give me an error report that called out Cylance. Luckily I have access to administer our Cylance portal, so I was able to work through the issue to narrow down the problem.

Symptoms:

• When running an app from Xcode, the Simulator launches but the application does not launch within the Simulator
• Trying to stop the application from within Xcode does not work, and generates no messages
• Trying to re-run the application from within Xcode generates the following message: ‘An instance of “APPLICATION NAME” is already running. Choose “Stop” to terminate and launch a new instance.’ But pressing Stop does nothing.
• Xcode will not quit, and eventually the user must Force Quit to exit Xcode
• Within the OS X console, the following messages are displayed:

6/3/16 7:35:38.000 PM kernel[0]: AMFI: com.apple.dt.ins(pid 2239) - [deny-mmap] main process is a platform binary, but mapped executable file is not: /Library/Application Support/Cylance/Desktop/CyMemDef.dylib

6/3/16 7:35:38.000 PM kernel[0]: AMFI: com.apple.dt.ins(pid 2239) - [deny-mmap] mapped file has team identifier XXXX: /Library/Application Support/Cylance/Desktop/CyMemDef.dylib

Resolution:

The problem is caused by Memory Protection being turned on within the policy assigned to the Mac within the Cylance portal.

To resolve the issue, place the Mac into a zone/policy that does not have Memory Protection turned on. Auto Quarantine and Protection Settings can be left on.

During my testing, I was not able to come up with a list of exclusions that allowed me to leave Memory Protection on, so I ended up disabling it completely.