dotnet new --install results in a null ref

[pranavkm]

Discovered this as part of ASP.NET Core's builds:

D:\temp\buildops\aspnetcore\.dotnet\dotnet.exe new --install "D:\temp\buildops\aspnetcore\artifacts\packages\Debug\Shipping\Microsoft.DotNet.Web.Client.ItemTemplates.6.0.0-dev.nupkg" --debug:custom-hive "D:\temp\buildops\aspnetcore\src\ProjectTemplates\test\bin\Debug\net6.0\TestTemplates\\Hives\f65c109b-ee07-4fbb-b6df-1fd0c6472fac\.templateengine" [D:\temp\buildops\aspnetcore\src\ProjectTemplates\test\bin\Debug\net6.0\]
Getting ready...
The following template packages will be installed:
  D:\temp\buildops\aspnetcore\artifacts\packages\Debug\Shipping\Microsoft.DotNet.Web.Client.ItemTemplates.6.0.0-dev.nupkg

[ERROR] Object reference not set to an instance of an object.
[ERROR]    at Microsoft.TemplateEngine.Cli.TemplatePackageCoordinator.EnterInstallFlowAsync(INewCommandInput commandInput, CancellationToken cancellationToken) in Microsoft.TemplateEngine.Cli.dll:token 0x600018b+0x2f6
[ERROR]    at Microsoft.TemplateEngine.Cli.New3Command.ExecuteAsync() in Microsoft.TemplateEngine.Cli.dll:token 0x6000148+0x381
[ERROR]    at Microsoft.TemplateEngine.Cli.CommandParsing.NewCommandInputCli.<>c__DisplayClass102_0.<<OnExecute>b__0>d.MoveNext() in Microsoft.TemplateEngine.Cli.dll:token 0x60004b5+0x71

SDK v6.0.100-preview.4.21214.10

[pranavkm]

This is blocking our ability to update to a new version of the SDK / pick up a new runtime. Possibly related to this: https://github.com/dotnet/sdk/issues/16906

[DavidKarlas]

We did some big refactoring recently, that went out to SDK, I will get on fixing this right away, thank you for reporting

[DavidKarlas]

This is now fixed with #3040 and propagated to SDK.