title: azure devops Build error with asp.net core 2.2
body: <p>I am trying to build ASP.NET core 2.2 project using Azure Devops build pipeline.
  I am getting one weird error "error CS0234: The type or namespace name 'Extensions' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?)"
  It is getting build successfully through VS 2017..I am using VS2017 hosted agent in build task. 
  I deployed same project in Azure App service directly from VS 2017 and it worked their as well..
  Thanks in advance for you help.</p>