PowerShell completions generate bogus completion flags for all commands

[pingzing]

Problem The generated completions for PowerShell incorrectly contain the following completions for the following flags for every option:

• -h
• h
• --help
• help
• -V
• V
• version
• --version

...even for commands that do not accept those flags. The result is that if I type

> rustup help

...and then press Tab, I get -h as a suggested autocompletion, which is invalid.

Steps

1. rustup completions powershell
2. See output. I'll attach the full contents of the generated completions in a follow-up comment.

Possible Solution(s) At a guess (I couldn't find where in the repo the completions are actually created), it seems like these four completions get added to every possible command, instead of only those that actually accept it:

[CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
[CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
[CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
[CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')

Notes

Output of rustup --version: rustup 1.18.3 (435397f48 2019-05-22) Output of rustup show:

Default host: x86_64-pc-windows-msvc

installed toolchains
--------------------

stable-x86_64-pc-windows-msvc
nightly-x86_64-pc-windows-msvc

active toolchain
----------------

stable-x86_64-pc-windows-msvc (default)
rustc 1.31.0 (abe02cefd 2018-12-04)

[pingzing]

The generated completions:

(Also, I have to give kudos to whoever wrote the generator for this. The output is very readable!)

using namespace System.Management.Automation
using namespace System.Management.Automation.Language

Register-ArgumentCompleter -Native -CommandName 'rustup' -ScriptBlock {
    param($wordToComplete, $commandAst, $cursorPosition)

    $commandElements = $commandAst.CommandElements
    $command = @(
        'rustup'
        for ($i = 1; $i -lt $commandElements.Count; $i++) {
            $element = $commandElements[$i]
            if ($element -isnot [StringConstantExpressionAst] -or
                $element.StringConstantType -ne [StringConstantType]::BareWord -or
                $element.Value.StartsWith('-')) {
                break
            }
            $element.Value
        }) -join ';'

    $completions = @(switch ($command) {
            'rustup' {
                [CompletionResult]::new('-v', 'v', [CompletionResultType]::ParameterName, 'Enable verbose output')
                [CompletionResult]::new('--verbose', 'verbose', [CompletionResultType]::ParameterName, 'Enable verbose output')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('show', 'show', [CompletionResultType]::ParameterValue, 'Show the active and installed toolchains')
                [CompletionResult]::new('install', 'install', [CompletionResultType]::ParameterValue, 'Update Rust toolchains')
                [CompletionResult]::new('uninstall', 'uninstall', [CompletionResultType]::ParameterValue, 'Uninstall Rust toolchains')
                [CompletionResult]::new('update', 'update', [CompletionResultType]::ParameterValue, 'Update Rust toolchains and rustup')
                [CompletionResult]::new('default', 'default', [CompletionResultType]::ParameterValue, 'Set the default toolchain')
                [CompletionResult]::new('toolchain', 'toolchain', [CompletionResultType]::ParameterValue, 'Modify or query the installed toolchains')
                [CompletionResult]::new('target', 'target', [CompletionResultType]::ParameterValue, 'Modify a toolchain''s supported targets')
                [CompletionResult]::new('component', 'component', [CompletionResultType]::ParameterValue, 'Modify a toolchain''s installed components')
                [CompletionResult]::new('override', 'override', [CompletionResultType]::ParameterValue, 'Modify directory toolchain overrides')
                [CompletionResult]::new('run', 'run', [CompletionResultType]::ParameterValue, 'Run a command with an environment configured for a given toolchain')
                [CompletionResult]::new('which', 'which', [CompletionResultType]::ParameterValue, 'Display which binary will be run for a given command')
                [CompletionResult]::new('doc', 'doc', [CompletionResultType]::ParameterValue, 'Open the documentation for the current toolchain')
                [CompletionResult]::new('self', 'self', [CompletionResultType]::ParameterValue, 'Modify the rustup installation')
                [CompletionResult]::new('telemetry', 'telemetry', [CompletionResultType]::ParameterValue, 'rustup telemetry commands')
                [CompletionResult]::new('set', 'set', [CompletionResultType]::ParameterValue, 'Alter rustup settings')
                [CompletionResult]::new('completions', 'completions', [CompletionResultType]::ParameterValue, 'Generate completion scripts for your shell')
                [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
                break
            }
            'rustup;show' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('active-toolchain', 'active-toolchain', [CompletionResultType]::ParameterValue, 'Show the active toolchain')
                [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
                break
            }
            'rustup;show;active-toolchain' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;show;help' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;install' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;uninstall' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;update' {
                [CompletionResult]::new('--no-self-update', 'no-self-update', [CompletionResultType]::ParameterName, 'Don''t perform self update when running the `rustup` command')
                [CompletionResult]::new('--force', 'force', [CompletionResultType]::ParameterName, 'Force an update, even if some components are missing')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;default' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;toolchain' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List installed toolchains')
                [CompletionResult]::new('install', 'install', [CompletionResultType]::ParameterValue, 'Install or update a given toolchain')
                [CompletionResult]::new('uninstall', 'uninstall', [CompletionResultType]::ParameterValue, 'Uninstall a toolchain')
                [CompletionResult]::new('link', 'link', [CompletionResultType]::ParameterValue, 'Create a custom toolchain by symlinking to a directory')
                [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
                break
            }
            'rustup;toolchain;list' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;toolchain;install' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;toolchain;uninstall' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;toolchain;link' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;toolchain;help' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;target' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List installed and available targets')
                [CompletionResult]::new('add', 'add', [CompletionResultType]::ParameterValue, 'Add a target to a Rust toolchain')
                [CompletionResult]::new('remove', 'remove', [CompletionResultType]::ParameterValue, 'Remove a target from a Rust toolchain')
                [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
                break
            }
            'rustup;target;list' {
                [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;target;add' {
                [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;target;remove' {
                [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;target;help' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;component' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List installed and available components')
                [CompletionResult]::new('add', 'add', [CompletionResultType]::ParameterValue, 'Add a component to a Rust toolchain')
                [CompletionResult]::new('remove', 'remove', [CompletionResultType]::ParameterValue, 'Remove a component from a Rust toolchain')
                [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
                break
            }
            'rustup;component;list' {
                [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;component;add' {
                [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
                [CompletionResult]::new('--target', 'target', [CompletionResultType]::ParameterName, 'target')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;component;remove' {
                [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
                [CompletionResult]::new('--target', 'target', [CompletionResultType]::ParameterName, 'target')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;component;help' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;override' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List directory toolchain overrides')
                [CompletionResult]::new('set', 'set', [CompletionResultType]::ParameterValue, 'Set the override toolchain for a directory')
                [CompletionResult]::new('unset', 'unset', [CompletionResultType]::ParameterValue, 'Remove the override toolchain for a directory')
                [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
                break
            }
            'rustup;override;list' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;override;set' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;override;unset' {
                [CompletionResult]::new('--path', 'path', [CompletionResultType]::ParameterName, 'Path to the directory')
                [CompletionResult]::new('--nonexistent', 'nonexistent', [CompletionResultType]::ParameterName, 'Remove override toolchain for all nonexistent directories')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;override;help' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;run' {
                [CompletionResult]::new('--install', 'install', [CompletionResultType]::ParameterName, 'Install the requested toolchain if needed')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;which' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;doc' {
                [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
                [CompletionResult]::new('--path', 'path', [CompletionResultType]::ParameterName, 'Only print the path to the documentation')
                [CompletionResult]::new('--book', 'book', [CompletionResultType]::ParameterName, 'The Rust Programming Language book')
                [CompletionResult]::new('--std', 'std', [CompletionResultType]::ParameterName, 'Standard library API documentation')
                [CompletionResult]::new('--reference', 'reference', [CompletionResultType]::ParameterName, 'The Rust Reference')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;self' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('update', 'update', [CompletionResultType]::ParameterValue, 'Download and install updates to rustup')
                [CompletionResult]::new('uninstall', 'uninstall', [CompletionResultType]::ParameterValue, 'Uninstall rustup.')
                [CompletionResult]::new('upgrade-data', 'upgrade-data', [CompletionResultType]::ParameterValue, 'Upgrade the internal data format.')
                [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
                break
            }
            'rustup;self;update' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;self;uninstall' {
                [CompletionResult]::new('-y', 'y', [CompletionResultType]::ParameterName, 'y')
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;self;upgrade-data' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;self;help' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;telemetry' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('enable', 'enable', [CompletionResultType]::ParameterValue, 'Enable rustup telemetry')
                [CompletionResult]::new('disable', 'disable', [CompletionResultType]::ParameterValue, 'Disable rustup telemetry')
                [CompletionResult]::new('analyze', 'analyze', [CompletionResultType]::ParameterValue, 'Analyze stored telemetry')
                [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
                break
            }
            'rustup;telemetry;enable' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;telemetry;disable' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;telemetry;analyze' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;telemetry;help' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;set' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('default-host', 'default-host', [CompletionResultType]::ParameterValue, 'The triple used to identify toolchains when not specified')
                [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
                break
            }
            'rustup;set;default-host' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;set;help' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;completions' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
            'rustup;help' {
                [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
                [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
                [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
                break
            }
        })

    $completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
    Sort-Object -Property ListItemText
}

[kinnison]

The completions are generated by clap, so I'm not sure why it would be wrong unless it's a bug in clap.

Could you please try writing a simple clap app and see if the completions come out properly; and if not, file a bug on clap and link it to this so that we can track it?

[workingjubilee]

@rustbot label: +O-windows

[leij0318]

生成的补全：

（另外，我必须向为此编写生成器的人表示敬意。输出非常可读！）

using namespace System.Management.Automation using namespace System.Management.Automation.Language

Register-ArgumentCompleter -Native -CommandName 'rustup' -ScriptBlock { param($wordToComplete, $commandAst, $cursorPosition)

$commandElements = $commandAst.CommandElements
$command = @(
    'rustup'
    for ($i = 1; $i -lt $commandElements.Count; $i++) {
        $element = $commandElements[$i]
        if ($element -isnot [StringConstantExpressionAst] -or
            $element.StringConstantType -ne [StringConstantType]::BareWord -or
            $element.Value.StartsWith('-')) {
            break
        }
        $element.Value
    }) -join ';'

$completions = @(switch ($command) {
        'rustup' {
            [CompletionResult]::new('-v', 'v', [CompletionResultType]::ParameterName, 'Enable verbose output')
            [CompletionResult]::new('--verbose', 'verbose', [CompletionResultType]::ParameterName, 'Enable verbose output')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('show', 'show', [CompletionResultType]::ParameterValue, 'Show the active and installed toolchains')
            [CompletionResult]::new('install', 'install', [CompletionResultType]::ParameterValue, 'Update Rust toolchains')
            [CompletionResult]::new('uninstall', 'uninstall', [CompletionResultType]::ParameterValue, 'Uninstall Rust toolchains')
            [CompletionResult]::new('update', 'update', [CompletionResultType]::ParameterValue, 'Update Rust toolchains and rustup')
            [CompletionResult]::new('default', 'default', [CompletionResultType]::ParameterValue, 'Set the default toolchain')
            [CompletionResult]::new('toolchain', 'toolchain', [CompletionResultType]::ParameterValue, 'Modify or query the installed toolchains')
            [CompletionResult]::new('target', 'target', [CompletionResultType]::ParameterValue, 'Modify a toolchain''s supported targets')
            [CompletionResult]::new('component', 'component', [CompletionResultType]::ParameterValue, 'Modify a toolchain''s installed components')
            [CompletionResult]::new('override', 'override', [CompletionResultType]::ParameterValue, 'Modify directory toolchain overrides')
            [CompletionResult]::new('run', 'run', [CompletionResultType]::ParameterValue, 'Run a command with an environment configured for a given toolchain')
            [CompletionResult]::new('which', 'which', [CompletionResultType]::ParameterValue, 'Display which binary will be run for a given command')
            [CompletionResult]::new('doc', 'doc', [CompletionResultType]::ParameterValue, 'Open the documentation for the current toolchain')
            [CompletionResult]::new('self', 'self', [CompletionResultType]::ParameterValue, 'Modify the rustup installation')
            [CompletionResult]::new('telemetry', 'telemetry', [CompletionResultType]::ParameterValue, 'rustup telemetry commands')
            [CompletionResult]::new('set', 'set', [CompletionResultType]::ParameterValue, 'Alter rustup settings')
            [CompletionResult]::new('completions', 'completions', [CompletionResultType]::ParameterValue, 'Generate completion scripts for your shell')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;show' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('active-toolchain', 'active-toolchain', [CompletionResultType]::ParameterValue, 'Show the active toolchain')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;show;active-toolchain' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;show;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;install' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;uninstall' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;update' {
            [CompletionResult]::new('--no-self-update', 'no-self-update', [CompletionResultType]::ParameterName, 'Don''t perform self update when running the `rustup` command')
            [CompletionResult]::new('--force', 'force', [CompletionResultType]::ParameterName, 'Force an update, even if some components are missing')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;default' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List installed toolchains')
            [CompletionResult]::new('install', 'install', [CompletionResultType]::ParameterValue, 'Install or update a given toolchain')
            [CompletionResult]::new('uninstall', 'uninstall', [CompletionResultType]::ParameterValue, 'Uninstall a toolchain')
            [CompletionResult]::new('link', 'link', [CompletionResultType]::ParameterValue, 'Create a custom toolchain by symlinking to a directory')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;toolchain;list' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain;install' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain;uninstall' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain;link' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;target' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List installed and available targets')
            [CompletionResult]::new('add', 'add', [CompletionResultType]::ParameterValue, 'Add a target to a Rust toolchain')
            [CompletionResult]::new('remove', 'remove', [CompletionResultType]::ParameterValue, 'Remove a target from a Rust toolchain')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;target;list' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;target;add' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;target;remove' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;target;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;component' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List installed and available components')
            [CompletionResult]::new('add', 'add', [CompletionResultType]::ParameterValue, 'Add a component to a Rust toolchain')
            [CompletionResult]::new('remove', 'remove', [CompletionResultType]::ParameterValue, 'Remove a component from a Rust toolchain')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;component;list' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;component;add' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('--target', 'target', [CompletionResultType]::ParameterName, 'target')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;component;remove' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('--target', 'target', [CompletionResultType]::ParameterName, 'target')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;component;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;override' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List directory toolchain overrides')
            [CompletionResult]::new('set', 'set', [CompletionResultType]::ParameterValue, 'Set the override toolchain for a directory')
            [CompletionResult]::new('unset', 'unset', [CompletionResultType]::ParameterValue, 'Remove the override toolchain for a directory')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;override;list' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;override;set' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;override;unset' {
            [CompletionResult]::new('--path', 'path', [CompletionResultType]::ParameterName, 'Path to the directory')
            [CompletionResult]::new('--nonexistent', 'nonexistent', [CompletionResultType]::ParameterName, 'Remove override toolchain for all nonexistent directories')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;override;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;run' {
            [CompletionResult]::new('--install', 'install', [CompletionResultType]::ParameterName, 'Install the requested toolchain if needed')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;which' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;doc' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('--path', 'path', [CompletionResultType]::ParameterName, 'Only print the path to the documentation')
            [CompletionResult]::new('--book', 'book', [CompletionResultType]::ParameterName, 'The Rust Programming Language book')
            [CompletionResult]::new('--std', 'std', [CompletionResultType]::ParameterName, 'Standard library API documentation')
            [CompletionResult]::new('--reference', 'reference', [CompletionResultType]::ParameterName, 'The Rust Reference')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;self' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('update', 'update', [CompletionResultType]::ParameterValue, 'Download and install updates to rustup')
            [CompletionResult]::new('uninstall', 'uninstall', [CompletionResultType]::ParameterValue, 'Uninstall rustup.')
            [CompletionResult]::new('upgrade-data', 'upgrade-data', [CompletionResultType]::ParameterValue, 'Upgrade the internal data format.')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;self;update' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;self;uninstall' {
            [CompletionResult]::new('-y', 'y', [CompletionResultType]::ParameterName, 'y')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;self;upgrade-data' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;self;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;telemetry' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('enable', 'enable', [CompletionResultType]::ParameterValue, 'Enable rustup telemetry')
            [CompletionResult]::new('disable', 'disable', [CompletionResultType]::ParameterValue, 'Disable rustup telemetry')
            [CompletionResult]::new('analyze', 'analyze', [CompletionResultType]::ParameterValue, 'Analyze stored telemetry')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;telemetry;enable' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;telemetry;disable' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;telemetry;analyze' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;telemetry;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;set' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('default-host', 'default-host', [CompletionResultType]::ParameterValue, 'The triple used to identify toolchains when not specified')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;set;default-host' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;set;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;completions' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
    })

$completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
Sort-Object -Property ListItemText

}

Why do I get an error when I run PowerShell when I add these commands (rustup completions) to the end of the PowerShell $profile file?

The generated completions:

(Also, I have to give kudos to whoever wrote the generator for this. The output is very readable!)

using namespace System.Management.Automation using namespace System.Management.Automation.Language

Register-ArgumentCompleter -Native -CommandName 'rustup' -ScriptBlock { param($wordToComplete, $commandAst, $cursorPosition)

$commandElements = $commandAst.CommandElements
$command = @(
    'rustup'
    for ($i = 1; $i -lt $commandElements.Count; $i++) {
        $element = $commandElements[$i]
        if ($element -isnot [StringConstantExpressionAst] -or
            $element.StringConstantType -ne [StringConstantType]::BareWord -or
            $element.Value.StartsWith('-')) {
            break
        }
        $element.Value
    }) -join ';'

$completions = @(switch ($command) {
        'rustup' {
            [CompletionResult]::new('-v', 'v', [CompletionResultType]::ParameterName, 'Enable verbose output')
            [CompletionResult]::new('--verbose', 'verbose', [CompletionResultType]::ParameterName, 'Enable verbose output')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('show', 'show', [CompletionResultType]::ParameterValue, 'Show the active and installed toolchains')
            [CompletionResult]::new('install', 'install', [CompletionResultType]::ParameterValue, 'Update Rust toolchains')
            [CompletionResult]::new('uninstall', 'uninstall', [CompletionResultType]::ParameterValue, 'Uninstall Rust toolchains')
            [CompletionResult]::new('update', 'update', [CompletionResultType]::ParameterValue, 'Update Rust toolchains and rustup')
            [CompletionResult]::new('default', 'default', [CompletionResultType]::ParameterValue, 'Set the default toolchain')
            [CompletionResult]::new('toolchain', 'toolchain', [CompletionResultType]::ParameterValue, 'Modify or query the installed toolchains')
            [CompletionResult]::new('target', 'target', [CompletionResultType]::ParameterValue, 'Modify a toolchain''s supported targets')
            [CompletionResult]::new('component', 'component', [CompletionResultType]::ParameterValue, 'Modify a toolchain''s installed components')
            [CompletionResult]::new('override', 'override', [CompletionResultType]::ParameterValue, 'Modify directory toolchain overrides')
            [CompletionResult]::new('run', 'run', [CompletionResultType]::ParameterValue, 'Run a command with an environment configured for a given toolchain')
            [CompletionResult]::new('which', 'which', [CompletionResultType]::ParameterValue, 'Display which binary will be run for a given command')
            [CompletionResult]::new('doc', 'doc', [CompletionResultType]::ParameterValue, 'Open the documentation for the current toolchain')
            [CompletionResult]::new('self', 'self', [CompletionResultType]::ParameterValue, 'Modify the rustup installation')
            [CompletionResult]::new('telemetry', 'telemetry', [CompletionResultType]::ParameterValue, 'rustup telemetry commands')
            [CompletionResult]::new('set', 'set', [CompletionResultType]::ParameterValue, 'Alter rustup settings')
            [CompletionResult]::new('completions', 'completions', [CompletionResultType]::ParameterValue, 'Generate completion scripts for your shell')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;show' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('active-toolchain', 'active-toolchain', [CompletionResultType]::ParameterValue, 'Show the active toolchain')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;show;active-toolchain' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;show;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;install' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;uninstall' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;update' {
            [CompletionResult]::new('--no-self-update', 'no-self-update', [CompletionResultType]::ParameterName, 'Don''t perform self update when running the `rustup` command')
            [CompletionResult]::new('--force', 'force', [CompletionResultType]::ParameterName, 'Force an update, even if some components are missing')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;default' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List installed toolchains')
            [CompletionResult]::new('install', 'install', [CompletionResultType]::ParameterValue, 'Install or update a given toolchain')
            [CompletionResult]::new('uninstall', 'uninstall', [CompletionResultType]::ParameterValue, 'Uninstall a toolchain')
            [CompletionResult]::new('link', 'link', [CompletionResultType]::ParameterValue, 'Create a custom toolchain by symlinking to a directory')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;toolchain;list' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain;install' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain;uninstall' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain;link' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;toolchain;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;target' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List installed and available targets')
            [CompletionResult]::new('add', 'add', [CompletionResultType]::ParameterValue, 'Add a target to a Rust toolchain')
            [CompletionResult]::new('remove', 'remove', [CompletionResultType]::ParameterValue, 'Remove a target from a Rust toolchain')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;target;list' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;target;add' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;target;remove' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;target;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;component' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List installed and available components')
            [CompletionResult]::new('add', 'add', [CompletionResultType]::ParameterValue, 'Add a component to a Rust toolchain')
            [CompletionResult]::new('remove', 'remove', [CompletionResultType]::ParameterValue, 'Remove a component from a Rust toolchain')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;component;list' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;component;add' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('--target', 'target', [CompletionResultType]::ParameterName, 'target')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;component;remove' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('--target', 'target', [CompletionResultType]::ParameterName, 'target')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;component;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;override' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('list', 'list', [CompletionResultType]::ParameterValue, 'List directory toolchain overrides')
            [CompletionResult]::new('set', 'set', [CompletionResultType]::ParameterValue, 'Set the override toolchain for a directory')
            [CompletionResult]::new('unset', 'unset', [CompletionResultType]::ParameterValue, 'Remove the override toolchain for a directory')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;override;list' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;override;set' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;override;unset' {
            [CompletionResult]::new('--path', 'path', [CompletionResultType]::ParameterName, 'Path to the directory')
            [CompletionResult]::new('--nonexistent', 'nonexistent', [CompletionResultType]::ParameterName, 'Remove override toolchain for all nonexistent directories')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;override;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;run' {
            [CompletionResult]::new('--install', 'install', [CompletionResultType]::ParameterName, 'Install the requested toolchain if needed')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;which' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;doc' {
            [CompletionResult]::new('--toolchain', 'toolchain', [CompletionResultType]::ParameterName, 'Toolchain name, such as ''stable'', ''nightly'', or ''1.8.0''. For more information see `rustup help toolchain`')
            [CompletionResult]::new('--path', 'path', [CompletionResultType]::ParameterName, 'Only print the path to the documentation')
            [CompletionResult]::new('--book', 'book', [CompletionResultType]::ParameterName, 'The Rust Programming Language book')
            [CompletionResult]::new('--std', 'std', [CompletionResultType]::ParameterName, 'Standard library API documentation')
            [CompletionResult]::new('--reference', 'reference', [CompletionResultType]::ParameterName, 'The Rust Reference')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;self' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('update', 'update', [CompletionResultType]::ParameterValue, 'Download and install updates to rustup')
            [CompletionResult]::new('uninstall', 'uninstall', [CompletionResultType]::ParameterValue, 'Uninstall rustup.')
            [CompletionResult]::new('upgrade-data', 'upgrade-data', [CompletionResultType]::ParameterValue, 'Upgrade the internal data format.')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;self;update' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;self;uninstall' {
            [CompletionResult]::new('-y', 'y', [CompletionResultType]::ParameterName, 'y')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;self;upgrade-data' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;self;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;telemetry' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('enable', 'enable', [CompletionResultType]::ParameterValue, 'Enable rustup telemetry')
            [CompletionResult]::new('disable', 'disable', [CompletionResultType]::ParameterValue, 'Disable rustup telemetry')
            [CompletionResult]::new('analyze', 'analyze', [CompletionResultType]::ParameterValue, 'Analyze stored telemetry')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;telemetry;enable' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;telemetry;disable' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;telemetry;analyze' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;telemetry;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;set' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('default-host', 'default-host', [CompletionResultType]::ParameterValue, 'The triple used to identify toolchains when not specified')
            [CompletionResult]::new('help', 'help', [CompletionResultType]::ParameterValue, 'Prints this message or the help of the given subcommand(s)')
            break
        }
        'rustup;set;default-host' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;set;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;completions' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
        'rustup;help' {
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Prints help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Prints version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Prints version information')
            break
        }
    })

$completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
Sort-Object -Property ListItemText

}

Why do I get an error when I run PowerShell when I add these commands (rustup completions) to the end of the PowerShell $profile file? Is it possible that the PS script generated by rustup completions is incorrect?

Friends, can you tell me how to solve this problem? This error is the same as the error I get when I use the “fnm completions” command?

[ChrisDenton]

You can put the completions in a separate file then can use dot sourcing to import it in to the $profile file. E.g. add the following to the $profile file:

. path\to\rust-completions.ps1

Use the real path instead of path\to\rust-completions.ps1.