Migrations don't compile. 'Unable to create a manifest resource name for %MIGRATION_FILE%.resx'. Could not find a part of the path '%MIGRATION_FILE%%.cs'

We are getting the following build errors when trying to compile our EF6 project on .NET Core Preview 9 (also tested nightly build 6.3.0-rc1-19455-01, tested both Windows and Mac).

  Microsoft.CSharp.CurrentVersion.targets(100, 9): [MSB3041] Unable to create a manifest resource name for "Migrations\201806250240525_MigrationName1.resx". Could not find a part of the path 'C:\...PathToProject...\Migrations\Migrations\###############_MigrationName1.cs'.
  Microsoft.CSharp.CurrentVersion.targets(100, 9): [MSB3041] Unable to create a manifest resource name for "Migrations\201806250240525_MigrationName2.resx". Could not find a part of the path 'C:\...PathToProject...\Migrations\Migrations\###############_MigrationName2.cs'.
...
  Microsoft.CSharp.CurrentVersion.targets(100, 9): [MSB3041] Unable to create a manifest resource name for "Migrations\201806250240525_MigrationName5.resx". Could not find a part of the path 'C:\...PathToProject...\Migrations\Migrations\###############_MigrationName5.cs'.

It seems the paths being looked for includes ‘Migrations\Migrations\’ twice, which indeed doesn’t exist.

Further technical details

EF version: Tried both 6.3.0-preview9-19423-04 and 6.3.0-rc1-19455-01 Database Provider: System.Data.SqlClient (SQL Server) Operating system: Tried both Windows 10 and MacOS Mojave 10.14.6 IDE: Rider 2019.2.2

[marchy]

@divega confirmed that putting the files in the root directory avoids the problem – though obviously not an acceptable workaround since we have tens of migrations and would change + pollute the project structure.

The workaround of manually adding the dependent-upon references also avoids the issue, as mentioned above (more acceptable):

<ItemGroup>
    <!-- TEMP: workaround for https://github.com/microsoft/msbuild/issues/4488 -->
    <EmbeddedResource Update="Migrations\###############_MigrationName1.resx">
      <DependentUpon>###############_MigrationName1.cs</DependentUpon>
    </EmbeddedResource>

    ....

    <EmbeddedResource Update="Migrations\###############_MigrationName5.resx">
      <DependentUpon>###############_MigrationName5.cs</DependentUpon>
    </EmbeddedResource>
  </ItemGroup>

[bricelam]

The resource names will be wrong (as they were in preview8) causing new ResourceManager(typeof(MyMigrationClass)) to fail