'Safe handle has been closed' when stopping debugger while in a dynamicparam section in v2.2

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues, especially the pinned issues.

Exception report

Last 200 Keys:

<omitted irrelevant keystrokes>
 f o o Spacebar - b Tab

### Exception

System.ObjectDisposedException: Safe handle has been closed
   at System.Threading.WaitHandle.WaitMultiple(WaitHandle[] waitHandles, Int32 millisecondsTimeout, Boolean exitContext, Boolean WaitAll)
   at System.Threading.WaitHandle.WaitAny(WaitHandle[] waitHandles, Int32 millisecondsTimeout, Boolean exitContext)
   at Microsoft.PowerShell.PSConsoleReadLine.ReadKey()
   at Microsoft.PowerShell.PSConsoleReadLine.InputLoop()
   at Microsoft.PowerShell.PSConsoleReadLine.ReadLine(Runspace runspace, EngineIntrinsics engineIntrinsics, CancellationToken cancellationToken, Nullable`1 lastRunStatus)

Screenshot

N/A

Environment data

PS Version: 5.1.19041.1320
PS HostName: Visual Studio Code Host
PSReadLine Version: 2.2.0-beta4
PSReadLine EditMode: Windows
OS: 10.0.19041.1 (WinBuild.160101.0800)
BufferWidth: 227
BufferHeight: 28

Steps to reproduce

• Use VS Code with PowerShell Preview 2021.12.0 extension
• Create a function with dynamic parameters, e.g.:

function foo
{
    [CmdletBinding()]
    param ()

    dynamicparam
    {
        $DynParams = [Management.Automation.RuntimeDefinedParameterDictionary]::new()

        $DynParam = [Management.Automation.RuntimeDefinedParameter]::new(
            'bar',
            [string],
            [Collections.ObjectModel.Collection[System.Attribute]]::new()
        )

        $DynParams.Add($DynParam.Name, $DynParam)

        return $DynParams
    }
}

• Put a breakpoint within the dynamicparam block and start an interactive session
• Invoke the dynamic parameter with foo - and hit <tab>
• Debugger stops in the dynamicparam block, as expected
• Stop the debugger with <Ctrl-F5>
• Integrated console returns, but shows error message

Expected behavior

No exception

Actual behavior

Error shown

[daxian-dbw]

It’s not a supported scenario. PSConsoleReadLine.ReadLine is a static method, but the operations are all around a singleton of PSConsoleReadLine. Reentry of the PSReadLine means corrupting the text buffer of the singleton and more, so it won’t work.

Is it possible to identify that we are re-entering the ReadLine method? If so, how about use the old legacy readline in that rare scenario?

[SeeminglyScience]

It’d be nice to have a better error message here, but this is still a case of needing re-entrance in PSReadLine. Now that attach to process works, I think that’s the best way to debug argument completers, tab completion in general, and PSReadLine key handlers.