Instruments: No profile from spinning apps

Summary

Instruments offers you an automatic Time Profile when you set it to automatically trace spinning applications.I can't find the resulting trace file.


Where can I find the generated trace file? Or how can I force it to be written?


Detail

The Instruments preferences (and custom Dock popup) include the option "Automatically Time Profile Spinning Applications." The idea, as I understand, is that if the OS detects an application hasn't serviced its main runloop in a certain amount of time (is unresponsive to user actions), it changes the cursor to what we used to call a "beachball" (the spinning color wheel).


When the profile-spinning-apps option is set, Instruments is supposed to start a Time Profile of the problem application, stopping when the blockage clears. The trace is supposed to be in ~/Library/Application Support/Instruments/Unimported (I also looked in ~/Desktop). What I see is:

  • A bezel HUD appears when an app spins, indicating the name of the problem application.
  • No recent .trace or .dtps file appears in either location. (I also looked in the Application Support directory for root.)

The problem application is Xcode 9.3 — the Playground hangs constantly — but that's another subject.


What may be relevant is that the playground is configured for iOS (and therefore a simulator). Doing a find from ~/Library/Developer for either extension turned up nothing.


Yesterday I backed off every Xcode-related file and directory I could think of from ~/Library. It didn't help my problems with either Playground or Instruments.


Question (again)

Where can I find the generated trace file? Or how can I force it to be created?

Instruments: No profile from spinning apps
 
 
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