On Apple silicon macOS 27.2 build 26B123, consider a launchd-managed supervisor making one posix_spawn call to start a dedicated worker. The supervisor may exit before receiving the PID or before it can wait for the child. Is there a supported API or OS-issued record that lets a surviving observer verify what happened to that one attempt? Can the observer distinguish an attempt that created no child from one that created a child before the caller received the PID? What stable identifier ties creation and any exec transition to that attempt? If the supervisor exits, which component actually performs the reap? Can the observer verify the same child's exit status, completed reap, and absence of surviving descendants after restarting? Please identify the supported macOS versions, privileges, record source, correlation fields, and any loss or retention limits. If no supported record covers a step, please identify that boundary.

How can a macOS observer verify child creation and reap after the spawning process exits?

On Apple silicon macOS 27.2 build 26B123, consider a launchd-managed supervisor making one posix_spawn call to start a dedicated worker. The supervisor may exit before receiving the PID or before it can wait for the child. Is there a supported API or OS-issued record that lets a surviving observer verify what happened to that one attempt?

Can the observer distinguish an attempt that created no child from one that created a child before the caller received the PID? What stable identifier ties creation and any exec transition to that attempt?
If the supervisor exits, which component actually performs the reap? Can the observer verify the same child's exit status, completed reap, and absence of surviving descendants after restarting?

Please identify the supported macOS versions, privileges, record source, correlation fields, and any loss or retention limits. If no supported record covers a step, please identify that boundary.