Reference data gathered on macOS (Darwin 25.6.0) against fish master (35fd72ad0). Only commands shipped with macOS in /bin, /usr/bin, /sbin, /usr/sbin were considered; Homebrew-installed tools were excluded.
Method: each completion file was loaded with PATH restricted to the system directories, the options it offered were collected, and every long option was checked against the macOS man page. Every hit was then re-verified by running the real binary with that option in a read-only way (an invalid option makes