CURLMOPT_PUSHDATA(3) on macOS
The text a8c2aafb9b68, as macOS 11.5, macOS 11.4, macOS 11.3, macOS 11.2, macOS 11.1, macOS 11.0.1, macOS 10.15.6, macOS 10.15.5, macOS 10.15.4, macOS 10.15.3, macOS 10.15.2, macOS 10.15.1, macOS 10.15 shipped it.
pointer to pass to push callback