What are "stackshots" for mac?

Solution 1:

You're pretty close. A "stackshot" is a recording of the call stack trace of processes on the system (including kernel threads), which is useful for debugging purposes as it provides insight into what the application is doing at the time that the stackshot was taken. macOS captures these automatically when the system detects certain types of hangs using a utility called spindump(8) (recently, it seems the original data source is tailspin(8)). Depending on your privacy settings, these get uploaded periodically for Apple to aggregate and analyze hangs across the system.