$ pub outdated random_argument
[ERR] Command "outdated" does not take any arguments.
[ERR] 
[ERR] Usage: pub outdated [options]
[ERR] -h, --help                         Print this usage information.
[ERR]     --[no-]color                   Whether to color the output.
[ERR]                                    Defaults to color when connected to a
[ERR]                                    terminal, and no-color otherwise.
[ERR]     --[no-]dependency-overrides    Show resolutions with `dependency_overrides`.
[ERR]                                    (defaults to on)
[ERR]     --[no-]dev-dependencies        Take dev dependencies into account.
[ERR]                                    (defaults to on)
[ERR]     --json                         Output the results using a json format.
[ERR]     --mode=<PROPERTY>              Highlight versions with PROPERTY.
[ERR]                                    Only packages currently missing that PROPERTY
[ERR]                                    will be included unless --show-all.
[ERR]                                    [outdated (default), null-safety]
[ERR]     --[no-]prereleases             Include prereleases in latest version.
[ERR]                                    (defaults to on in --mode=null-safety).
[ERR]     --[no-]show-all                Include dependencies that are already
[ERR]                                    fullfilling --mode.
[ERR]     --[no-]transitive              Show transitive dependencies.
[ERR]                                    (defaults to off in --mode=null-safety).
[ERR] 
[ERR] Run "pub help" to see global options.
[ERR] See https://dart.dev/tools/pub/cmd/pub-outdated for detailed documentation.
[Exit code] 64

$ pub outdated --bad_flag
[ERR] Could not find an option named "bad_flag".
[ERR] 
[ERR] Usage: pub outdated [options]
[ERR] -h, --help                         Print this usage information.
[ERR]     --[no-]color                   Whether to color the output.
[ERR]                                    Defaults to color when connected to a
[ERR]                                    terminal, and no-color otherwise.
[ERR]     --[no-]dependency-overrides    Show resolutions with `dependency_overrides`.
[ERR]                                    (defaults to on)
[ERR]     --[no-]dev-dependencies        Take dev dependencies into account.
[ERR]                                    (defaults to on)
[ERR]     --json                         Output the results using a json format.
[ERR]     --mode=<PROPERTY>              Highlight versions with PROPERTY.
[ERR]                                    Only packages currently missing that PROPERTY
[ERR]                                    will be included unless --show-all.
[ERR]                                    [outdated (default), null-safety]
[ERR]     --[no-]prereleases             Include prereleases in latest version.
[ERR]                                    (defaults to on in --mode=null-safety).
[ERR]     --[no-]show-all                Include dependencies that are already
[ERR]                                    fullfilling --mode.
[ERR]     --[no-]transitive              Show transitive dependencies.
[ERR]                                    (defaults to off in --mode=null-safety).
[ERR] 
[ERR] Run "pub help" to see global options.
[ERR] See https://dart.dev/tools/pub/cmd/pub-outdated for detailed documentation.
[Exit code] 64