Can´t generate migrations using .NET Core Tools MSBuild from the CLI

I can´t generate a new migration from a class library project even when setting a valid ASP.NET Core Web API application as a startup project.

Error message: Could not invoke this command on the startup project '{project-dir}'. This version of the Entity Framework Core .NET Command Line Tools does not support commands on class library projects in ASP.NET Core and .NET Core applications. See http://go.microsoft.com/fwlink/?LinkId=798221 for details and workarounds.

Steps to reproduce

• Execute the following command on the library project folder :

dotnet ef -s ../{asp.net core app dir} migrations add FirstMigration

Further technical details

EF Core version: 1.1.0 EF Core Tools version: 1.0.0-msbuild2-final Database Provider: Microsoft.EntityFrameworkCore.SqlServer Operating system: Mac OS 10.12.2 IDE: Visual Studio Code

[bricelam]

cd gis.database/
dotnet ef migrations add MyMigration --startup-project ../gis.web/

[shawty]

@bricelam - Hi Brice, can you give us an example please?

Iv’e just hit this in a dotnet core web app using npgsql, and I’m not exactly clear on how to proceed.

Actual Exception is:

Startup project 'gis.database.csproj' targets framework '.NETStandard'. This framework is not intended for execution and may fail to resolve runtime dependencie s. If so, specify a different project using the --startup-project option and try again. System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.EntityFrameworkCore.Design, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified. File name: 'Microsoft.EntityFrameworkCore.Design, Culture=neutral, PublicKeyToken=null' at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMar k& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) at System.Reflection.Assembly.Load(AssemblyName assemblyRef) at Microsoft.EntityFrameworkCore.Tools.ReflectionOperationExecutor..ctor(String assembly, String startupAssembly, String projectDir, String contentRootPath, String dataDirectory, String rootNamespace, String environment) at Microsoft.EntityFrameworkCore.Tools.Commands.ProjectCommandBase.CreateExecutor() at Microsoft.EntityFrameworkCore.Tools.Commands.MigrationsAddCommand.Execute() at Microsoft.DotNet.Cli.CommandLine.CommandLineApplication.Execute(String[] args) at Microsoft.EntityFrameworkCore.Tools.Program.Main(String[] args) Could not load file or assembly 'Microsoft.EntityFrameworkCore.Design, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.

My EF stuff is in a seperate .NETStandard class library, in a folder called “gis.database”, while the actual web app running standalone is in ‘…/gis.web/’

How can I make ef migrations run in this case, based on your comments above?