`PowerShell.Create()` returning null

Question

Added reference: PowerShellStandard.Library

Repro inside a default .net-core project:

// ...

using System.Management.Automation;
using System.Collections.ObjectModel;

// ...

public static void Main(string[] args)
{
    Collection<PSObject> output;
    using (PowerShell ps = PowerShell.Create())
    {
        ps.AddScript("$test = Get-Date; $test");
        output = ps.Invoke();
    }

// ...

I've tried it with or without the using block, but I end up with the same result: the Create method is not creating a PowerShell object, but it's also not throwing an exception.

Is this a common issue with the PowerShell .net-standard library? Is there a workaround or another way to solve my problem?

Additional info, this is also happening with the RunspaceFactory class CreateRunspace method as I was exploring a workaround with managing runspaces myself.

What happens if you run the same code portion (compiled for net core) from command line as regular user? — ZorgoZ
– ZorgoZ, Commented Aug 7, 2018 at 18:50
@ZorgoZ The same result when building a .net core console application (if that's what you meant?). — Maximilian Burszley
– Maximilian Burszley, Commented Aug 7, 2018 at 18:59
That was what I meant. Then my presumption related to permissions seems wrong. Sorry... — ZorgoZ
– ZorgoZ, Commented Aug 7, 2018 at 19:52

Patrick Meinecke · Accepted Answer · 2021-04-15 16:41:24Z

7

PowerShellStandard is a reference library, it's intended for projects that will be loaded into the same AppDomain as PowerShell. In those scenarios the required assemblies are already loaded, so it would be a waste to pull down the entire SDK.

In order to host PowerShell (or otherwise use PowerShell API's from outside a PowerShell session) you need to reference the PowerShell SDK (for PowerShell Core) or the GAC assemblies (for Windows PowerShell).

~~To reference the SDK, you need a nuget.config file in the base directory of your project that adds the PowerShell myget as a source. Here's an example~~

<?xml version="1.0" encoding="utf-8"?> <configuration> <packageSources> <clear /> <add key="nuget.org" value="https://api.nuget.org/v3/index.json" /> <add key="dotnet-core" value="https://www.myget.org/F/dotnet-core/api/v3/index.json" /> <add key="powershell-core" value="https://powershell.myget.org/F/powershell-core/api/v3/index.json" /> </packageSources> </configuration>

~~And~~ add a reference to the SDK in your csproj

<ItemGroup>
    <PackageReference Include="Microsoft.PowerShell.SDK" Version="7.1.3" />
</ItemGroup>

Update 04/15/2021

You don't need the nuget config anymore, the SDK is now available on nuget.

edited Apr 15, 2021 at 16:41

answered Aug 7, 2018 at 22:19

Patrick Meinecke

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1 Comment

Maximilian Burszley Over a year ago

Just a note, I eventually figured this out and the MyGet repo is still broken; missing the wsman and diagnostics repos as dependencies.

Sani Huttunen · Accepted Answer · 2018-08-07 21:12:40Z

4

Looking through the source of the PowerShellStandard Library I noticed the following lines:

public static System.Management.Automation.PowerShell Create ( System.Management.Automation.Runspaces.InitialSessionState initialSessionState ) { return default(System.Management.Automation.PowerShell); }
public static System.Management.Automation.PowerShell Create (  ) { return default(System.Management.Automation.PowerShell); }
public static System.Management.Automation.PowerShell Create ( System.Management.Automation.RunspaceMode runspace ) { return default(System.Management.Automation.PowerShell); }

Those will always return the default of the sealed PowerShell class and that will always be null.

This makes it that PowerShell isn't (fully) supported in PowerShellStandard Library 5.1.

Same is for RunspaceFactory.CreateRunspace.

edited Aug 7, 2018 at 21:12

answered Aug 7, 2018 at 20:34

Sani Huttunen

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5 Comments

Maximilian Burszley Over a year ago

PowerShellStandard.Library is a library targeting .net-standard2 so it should work across all .net implementations (for powershell 5 and 6). Give me a bit to test your suggestion.

Maximilian Burszley Over a year ago

Realized you're trying to re-target to powershell 6; this is not an answer to my problem case.

Maximilian Burszley Over a year ago

.net core doesn't need to, because the implementation is .net standard, so it is supported. Here's a related article from the official powershell github. It's possible to create multi-platform cmdlets using the library, but unable to use the other features (such as PowerShell and RunspaceFactory)

Maximilian Burszley Over a year ago

That is some terrible news. Looks like I will need to pursue another option (like using core apis). Thank you

Roman Kuzmin Over a year ago

Posted a question to the team github.com/PowerShell/PowerShellStandard/issues/46

Roman Kuzmin · Accepted Answer · 2018-08-16 16:20:23Z

1

Here is the recently released Microsoft.PowerShell.SDK 6.0.4.

It looks like it is designed for PowerShell hosting and related tasks. At least the question like code worked fine in my .NET Core application. This package reference is enough.

edited Aug 16, 2018 at 16:20

answered Aug 16, 2018 at 16:14

Roman Kuzmin

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