macOS: MallocStackLogging warning persists in v1.0.80

Summary

The following diagnostic still appears in Copilot CLI TUI windows on macOS with Copilot CLI v1.0.80:

copilot(<pid>) MallocStackLogging: can't turn off malloc stack logging because it was not enabled.

I observed it twice in succession from separate Copilot subprocesses. This appears to be a regression or incomplete fix for #4375, which was reported against v1.0.77 and closed as completed.

Steps to reproduce

1. Launch Copilot CLI on macOS.
2. Use the TUI normally so that Copilot invokes subprocesses or tools.
3. Observe the diagnostic written into the TUI output, sometimes repeatedly with different process IDs.

Expected behavior

Copilot should not call the macOS stack-logging shutdown function when malloc stack logging is not enabled, and no diagnostic should be written into the TUI.

Actual behavior

The diagnostic appears in the TUI:

MallocStackLogging: can't turn off malloc stack logging because it was not enabled.

Environment

• Copilot CLI: 1.0.80
• macOS: 15.6.1 (24G90)
• Architecture: arm64
• Installation: Homebrew cask; Copilot self-updated runtime reports v1.0.80
• MallocStackLogging: unset
• MallocNanoZone: 0

Related issue

• #4375

Start by reproducing the diagnostic on macOS with Copilot CLI v1.0.80, then compare the current behavior with the fix discussed in issue #4375. Trace the subprocess path that produces the TUI output and verify that the diagnostic no longer appears when MallocStackLogging is unset.