`dotnet-ef migrations add` starts entire application when CreateHostBuilder method is not present

TLTR When public static IHostBuilder CreateHostBuilder(string[] args) method is removed from Program.cs in a web api template project with dependencies on EF 6, generating migration with dotnet ef CLI tool starts the entire application instead of generating migration. In EF 5 this behaviour was not present.

Hello, I’ve encountered strange behaviour of the dotnet ef CLI tool after updating my application to EF 6. Program.cs in our microservices looks like this:

public class Program
{
    public static Task Main(string[] args) => WebHostHelper.BuildAndRunWebHostAsync<Startup>(args, validateDiConfigurationInDebug: true);
}

As you can see it lacks CreateHostBuilder(string[] args) because it wouldn’t be productive to add this method in all microservices. Instead, we provide a helper method as above. Also, what is important, our application is implementing IDesignTimeDbContextFactory in order to control creating of DbContext when migrations are being added (find simple reproduction here: https://github.com/marekott/dotnet-ef-add-migration-bug-reproduction). When application had dependency on EF 5 dotnet-ef migrations add Initial -v command produced valid migration (logs below). After updating to EF 6 the same command starts the entire application (logs below) that needs to be killed in order to finish producing migration (which in the end is a valid one). Adding CreateHostBuilder(string[] args) resolves this issue, application is not started and migration is generated. However, adding this method especially that it is not used and wasn’t needed for 3 years seem as a lazy solution.

Taking everything into consideration what is a reason for this strange behaviour? It seems like a bug, especially that it has worked previously.

Logs for EF 5

PS C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi> dotnet-ef migrations add Initial
Build started...
Build succeeded.
Done. To undo this action, use 'ef migrations remove'
PS C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi> dotnet-ef migrations add Initial -v
Using project 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj'.
Using startup project 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj'.
Writing 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\obj\SampleWebApi.csproj.EntityFrameworkCore.targets'...
dotnet msbuild /target:GetEFProjectMetadata /property:EFProjectMetadataFile=C:\Users\marek.ott\AppData\Local\Temp\tmp277A.tmp /verbosity:quiet /nologo C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj
Writing 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\obj\SampleWebApi.csproj.EntityFrameworkCore.targets'...
dotnet msbuild /target:GetEFProjectMetadata /property:EFProjectMetadataFile=C:\Users\marek.ott\AppData\Local\Temp\tmp2A4A.tmp /verbosity:quiet /nologo C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj
Build started...
dotnet build C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj /verbosity:quiet /nologo

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:02.28
Build succeeded.
dotnet exec --depsfile C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0\SampleWebApi.deps.json --additionalprobingpath C:\Users\marek.ott\.nuget\packages --runtimeconfig C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0\SampleWebApi.runtimeconfig.json C:\Users\marek.ott\.dotnet\tools\.store\dotnet-ef\6.0.5\dotnet-ef\6.0.5\tools\netcoreapp3.1\any\tools\netcoreapp2.0\any\ef.dll migrations add Initial --assembly C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0\SampleWebApi.dll --project C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj --startup-assembly C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0\SampleWebApi.dll --startup-project C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj --project-dir C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\ --root-namespace SampleWebApi --language C# --framework net6.0 --working-dir C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi --verbose
Using assembly 'SampleWebApi'.
Using startup assembly 'SampleWebApi'.
Using application base 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0'.
Using working directory 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi'.
Using root namespace 'SampleWebApi'.
Using project directory 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\'.
Remaining arguments: .
Finding DbContext classes...
Finding IDesignTimeDbContextFactory implementations...
Found IDesignTimeDbContextFactory implementation 'PostgresDbContextMigrationsFactory'.
Found DbContext 'SampleWebApiContext'.
Finding application service provider in assembly 'SampleWebApi'...
Finding Microsoft.Extensions.Hosting service provider...
No static method 'CreateHostBuilder(string[])' was found on class 'Program'.
No application service provider was found.
Finding DbContext classes in the project...
Using DbContext factory 'PostgresDbContextMigrationsFactory'.
Using context 'SampleWebApiContext'.
Finding design-time services for provider 'Npgsql.EntityFrameworkCore.PostgreSQL'...
Using design-time services from provider 'Npgsql.EntityFrameworkCore.PostgreSQL'.
Finding design-time services referenced by assembly 'SampleWebApi'...
Finding design-time services referenced by assembly 'SampleWebApi'...
No referenced design-time services were found.
Finding IDesignTimeServices implementations in assembly 'SampleWebApi'...
No design-time services were found.
DetectChanges starting for 'SampleWebApiContext'.
DetectChanges completed for 'SampleWebApiContext'.
Writing migration to 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\Migrations\20220526065812_Initial.cs'.
Writing model snapshot to 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\Migrations\SampleWebApiContextModelSnapshot.cs'.
'SampleWebApiContext' disposed.
Done. To undo this action, use 'ef migrations remove'

Logs for EF 6

dotnet-ef migrations add Initial -v
Using project 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj'.
Using startup project 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj'.
Writing 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\obj\SampleWebApi.csproj.EntityFrameworkCore.targets'...
dotnet msbuild /target:GetEFProjectMetadata /property:EFProjectMetadataFile=C:\Users\marek.ott\AppData\Local\Temp\tmp423C.tmp /verbosity:quiet /nologo C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj
Writing 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\obj\SampleWebApi.csproj.EntityFrameworkCore.targets'...
dotnet msbuild /target:GetEFProjectMetadata /property:EFProjectMetadataFile=C:\Users\marek.ott\AppData\Local\Temp\tmp4460.tmp /verbosity:quiet /nologo C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj
Build started...
dotnet build C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj /verbosity:quiet /nologo

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:01.60
Build succeeded.
dotnet exec --depsfile C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0\SampleWebApi.deps.json --additionalprobingpath C:\Users\marek.ott\.nuget\packages --runtimeconfig C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0\SampleWebApi.runtimeconfig.json C:\Users\marek.ott\.dotnet\tools\.store\dotnet-ef\6.0.5\dotnet-ef\6.0.5\tools\netcoreapp3.1\any\tools\netcoreapp2.0\any\ef.dll migrations add Initial --assembly C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0\SampleWebApi.dll --project C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj --startup-assembly C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0\SampleWebApi.dll --startup-project C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\SampleWebApi.csproj --project-dir C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\ --root-namespace SampleWebApi --language C# --framework net6.0 --working-dir C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi --verbose
Using assembly 'SampleWebApi'.
Using startup assembly 'SampleWebApi'.
Using application base 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\bin\Debug\net6.0'.
Using working directory 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi'.
Using root namespace 'SampleWebApi'.
Using project directory 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\'.
Remaining arguments: .
Finding DbContext classes...
Finding IDesignTimeDbContextFactory implementations...
Found IDesignTimeDbContextFactory implementation 'PostgresDbContextMigrationsFactory'.
Found DbContext 'SampleWebApiContext'.
Finding application service provider in assembly 'SampleWebApi'...
Finding Microsoft.Extensions.Hosting service provider...
Using environment 'Development'.
Hosting environment: Development
Content root path: C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi
Now listening on: http://localhost:5000
Now listening on: https://localhost:5001
Application started. Press Ctrl+C to shut down.
Application is shutting down...
PS C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi> System.InvalidOperationException: The entry point exited without ever building an IHost.
   at Microsoft.Extensions.Hosting.HostFactoryResolver.HostingListener.CreateHost()
   at Microsoft.Extensions.Hosting.HostFactoryResolver.<>c__DisplayClass10_0.<ResolveHostFactory>b__0(String[] args)
   at Microsoft.Extensions.Hosting.HostFactoryResolver.<>c__DisplayClass13_0.<ResolveServiceProviderFactory>b__3(String[] args)
   at Microsoft.EntityFrameworkCore.Design.Internal.AppServiceProviderFactory.CreateFromHosting(String[] args)
An error occurred while accessing the Microsoft.Extensions.Hosting services. Continuing without the application service provider. Error: The entry point exited without ever building an IHost.
No application service provider was found.
Finding DbContext classes in the project...
Using DbContext factory 'PostgresDbContextMigrationsFactory'.
Using context 'SampleWebApiContext'.
Finding design-time services referenced by assembly 'SampleWebApi'...
Finding design-time services referenced by assembly 'SampleWebApi'...
No referenced design-time services were found.
Finding design-time services for provider 'Npgsql.EntityFrameworkCore.PostgreSQL'...
Using design-time services from provider 'Npgsql.EntityFrameworkCore.PostgreSQL'.
Finding IDesignTimeServices implementations in assembly 'SampleWebApi'...
No design-time services were found.
DetectChanges starting for 'SampleWebApiContext'.
DetectChanges completed for 'SampleWebApiContext'.
Writing migration to 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\Migrations\20220526070035_Initial.cs'.
Writing model snapshot to 'C:\Users\marek.ott\Desktop\demo\SampleWebApi\SampleWebApi\Migrations\SampleWebApiContextModelSnapshot.cs'.
'SampleWebApiContext' disposed.
Done. To undo this action, use 'ef migrations remove'

My dotnet ef version is:

Entity Framework Core .NET Command-line Tools
6.0.5