I have a developer that is getting "Build failed." when running add-migration in a .NET Core EF project, with no explanation of why the build failed. How do you troubleshoot this error?
We have a few other developers using the same solution code (myself included) that have not issues with add-migration.
We've verified that the project builds, and the entire solution builds. We've done "dotnet restore" and rebuild all multiple times, in addition to restarting VS2015. We've verified that the correct default solution is selected both in Solution Explorer, and in the Package Manager Console drop-down. We've verified that he has the correct SDK installed on his machine. I'm at a loss as to what to check next...any time I've had a failure during add-migration I've gotten enough information to point me in the direction of what to check, but just "Build failed." is a fairly useless error output.
The developer ended up un-mapping the project from TFS, deleting it, and re-mapping it. It's now working for him.
It's because of other projects in your solutions. e.g If you have two projects in your solution as Project A and Project B. If Project A is not successful build and then Project B data migration will fail. So you should unload Project A and add the migration to Project B again.
I think this is not a good answer but hope this help.