Unable to add DbContext Model diagram - custom DbContext cannot be activated (EF Core 5)

[alecoronel]

We are trying out EFCore Power Tools for the first time in our .Net5 project with EF Core 5.

The project is able to use migrations and everything related to EF Core works fine, but alas I cannot use EF Core Power Tools since we are always getting the error below (when trying to add DbContext Model diagram via EFCore Power Tools) no matter how much we refactor the code and try different approaches regarding the DbContext DI setup.

The error is this;

System.ArgumentException: Error:
Microsoft.EntityFrameworkCore.Design.OperationException: Unable to create an object of type 'MyDbContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728
---> System.InvalidOperationException: Unable to resolve service for type 'Microsoft.EntityFrameworkCore.DbContextOptions`1[MyProject.DataAccess.MyDbContext]' while attempting to activate 'MyProject.DataAccess.MyDbContext'.

Steps to reproduce

Create a custom class derived from DbContext as usual. Register it in the ServiceCollection in Startup.ConfigureServices as recommended;

            var connection = new SqlConnection(Configuration.GetConnectionString("DefaultConnection"));
            var builder = new DbContextOptionsBuilder<MyDbContext>().UseSqlServer(connection);

            services.AddScoped<DbContextOptions<MyDbContext>>(_ => builder.Options);
            services.AddDbContext<MyDbContext, MyDbContext>(); // As AddDbContext for design time tooling to find it automatically

In Program.cs set it all up as you always do;

        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                    
         // (etc...)

Further technical details

EF Core Power Tools version: 2.5.406.0

Database engine: SQL Server

Visual Studio version: 2019 - 16.8.3

[ErikEJ]

Possible duplicate of this: #655 (comment)

[alecoronel]

Perfect, thanks, it was the exact same issue!

[ErikEJ]

I have updated the docs here: https://github.com/ErikEJ/EFCorePowerTools/wiki/Inspect-your-DbContext-model