Simplified output path (UseArtifactsOutput) isn't friendly with ef migrations

[virzak]

File a bug

When using simplified output path adding a migration results in:

Include your code

Run the following

Set up project

dotnet new classlib -o UseArtifactsOutput -f net8.0 --no-restore
cd UseArtifactsOutput
echo "<Project><PropertyGroup><UseArtifactsOutput>true</UseArtifactsOutput></PropertyGroup></Project>" > Directory.Build.props
dotnet add package Microsoft.EntityFrameworkCore.SqlServer --version 8.0.0-preview.3.23174.2
dotnet add package Microsoft.EntityFrameworkCore.Design --version 8.0.0-preview.3.23174.2
dotnet build

Notice that obj directory doesn't exist.

Create DbContext.cs with:

using Microsoft.EntityFrameworkCore;

public class MyDbContext : Microsoft.EntityFrameworkCore.DbContext
{
  public MyDbContext(DbContextOptions<MyDbContext> options) : base(options) { }
}

public class TemporaryDbContextFactory : Microsoft.EntityFrameworkCore.Design.IDesignTimeDbContextFactory<MyDbContext>
{
  // remove static if EF stops working
  public static MyDbContext Create()
  {
    var builder = new DbContextOptionsBuilder<MyDbContext>();
    var connection = @"Data Source=(localdb)\mssqlserverlocaldb;Initial Catalog=UseArtifactsOutput";
    builder.UseSqlServer(connection, opt => opt.CommandTimeout(500));
    var vwContext = new MyDbContext(builder.Options);
    return vwContext;
  }

  public MyDbContext CreateDbContext(string[] args) => Create();
}

This won't work

dotnet ef migrations add First

but this will, though unfriendly

dotnet ef migrations add First --msbuildprojectextensionspath .artifacts/obj/UseArtifactsOutput

Include verbose output

The error when not including msbuildprojectextensionspath is:

error MSB4057: The target "GetEFProjectMetadata" does not exist in the project.
Unable to retrieve project metadata. Ensure it's an SDK-style project. If you're using a custom BaseIntermediateOutputPath or MSBuildProjectExtensionsPath values, Use the --msbuildprojectextensionspath option.

Include provider and version information

EF Core version: 8.0.0-preview.3.23174.2
Database provider: Microsoft.EntityFrameworkCore.SqlServer
Target framework: 8.0.0-preview.3

[ajcvickers]

Note from triage: consider as part of #18840.

[KennethHoff]

Took me like 30 minutes to figure out why this didn't work :|

[YandyZaldivar]

The workaround of adding the option --msbuildprojectextensionspath artifacts/obj/UseArtifactsOutput is not working for me on latest preview, I am getting the same error described in the original post. In my case the DbContext is in a different assembly than main executable. Any hint other than not use artifacts output for now?

[ArturDorochowicz]

This is also broken when dotnet ef is executed by the SDK during publish.
My issue there: dotnet/sdk#37422 (I created it not knowing about this one)

[ArturDorochowicz]

The workaround of adding the option --msbuildprojectextensionspath artifacts/obj/UseArtifactsOutput is not working for me on latest preview,

I think I'm seeing the same in release version. Can't make it work. Ended up disabling artifacts output layout.

[IgorVyatkin]

It happens because ef tool uses hardcoded path to the obj folder (like Path.Combine(Path.GetDirectoryName(projectFile), "obj")) to create ?.csproj.EntityFrameworkCore.targets files.

This folder can be overridden by --msbuildprojectextensionspath and it works but if we use same project as a project and a startup project only. If we use 2 different projects, it doesn't work because ef writes .targets file to a folder set by --msbuildprojectextensionspath only but a migration creation looks for .target files for both projects.

As a dirty workaround try do not use a separate startup project and use --msbuildprojectextensionspath.

[aradalvand]

Isn't this basically the same as #23853?

[mungojam]

#23853 (comment) works for me when I have migrations/startup assembly in a different project to the context assembly. A nice workaround for now that also works with Rider UI EF tools