`extensions` `No such command`

[Shereef]

https://github.com/dotnet/upgrade-assistant/blob/main/docs/design/Extension_Management.md

$ dotnet tool update -g --add-source https://api.nuget.org/v3/index.json --ignore-failed-sources upgrade-assistant
Tool 'upgrade-assistant' was reinstalled with the latest stable version (version '0.5.261').

$ upgrade-assistant.exe --version
0.5.261.51392

$ upgrade-assistant.exe
USAGE:
    upgrade-assistant [OPTIONS] <COMMAND>

EXAMPLES:
    upgrade-assistant upgrade <PROJECT_PATH>
    upgrade-assistant upgrade <PROJECT_PATH> --operation Inplace --targetFramework net6.0
    upgrade-assistant upgrade <PROJECT_PATH> --operation SideBySide --targetFramework LTS --destination <NEW_PROJECT_NAME_OR_PATH>

OPTIONS:
    -h, --help       Prints help information
    -v, --version    Prints version information

COMMANDS:
    upgrade    Upgrade project or its features. This command lets you pick upgrade options and guides through upgrade process

$ upgrade-assistant.exe extensions

Error: Unknown command 'extensions'.

       extensions
       ^^^^^^^^^^ No such command

[jstedfast]

The docs in this repo are outdated and this command no longer exists. In fact, this repo is obsolete and no longer maintained.

[zane-woodard-drc]

@jstedfast How is this repo obsolete and unmaintained with no notice or even a mention in the README? There's still plenty of Microsoft docs pages pointing to this tool and no mention of it being deprecated anywhere.

Where's the new repo? Is there no CLI tool anymore?