efcore: dbcontext scaffold falsely states: "Missing required argument ''."

Entity Framework Core .NET Command-line Tools 6.0.0-preview.1.21102.2

Calling

dotnet ef dbcontext scaffold "context" provider

results in error message

Missing required argument '<PROVIDER>'.

Obviously that is not the case.

This behavior did not occur in the previous version (5.0.?).

Output with option --verbose: dotnet exec --depsfile D:\Source\Workspaces\Test\DbNQCore\DbNQCore\bin\Debug\net5.0\DbNQCore.deps.json --additionalprobingpath C:\Users\rbenjes\.nuget\packages --additionalprobingpath "C:\Program Files\dotnet\sdk\NuGetFallbackFolder" C:\Users\rbenjes\.dotnet\tools\.store\dotnet-ef\6.0.0-preview.1.21102.2\dotnet-ef\6.0.0-preview.1.21102.2\tools\netcoreapp3.1\any\tools\netcoreapp2.0\any\ef.dll dbcontext scaffold connection Microsoft.EntityFrameworkCore.SqlServer --assembly D:\Source\Workspaces\Test\DbNQCore\DbNQCore\bin\Debug\net5.0\DbNQCore.dll --startup-assembly D:\Source\Workspaces\Test\DbNQCore\DbNQCore\bin\Debug\net5.0\DbNQCore.dll --project-dir D:\Source\Workspaces\Test\DbNQCore\DbNQCore\ --language C# --working-dir D:\Source\Workspaces\Test\DbNQCore\DbNQCore --verbose --root-namespace DbNQCore Microsoft.EntityFrameworkCore.Tools.CommandException: Missing required argument '<PROVIDER>'. at Microsoft.EntityFrameworkCore.Tools.Commands.DbContextScaffoldCommand.Validate() at Microsoft.EntityFrameworkCore.Tools.Commands.CommandBase.<>c__DisplayClass0_0.<Configure>b__0(String[] args) at Microsoft.DotNet.Cli.CommandLine.CommandLineApplication.Execute(String[] args) at Microsoft.EntityFrameworkCore.Tools.Program.Main(String[] args) Missing required argument '<PROVIDER>'.