title: How is working the build pipeline folder system?
body: <p>I would like to understand how the build system works in Azure DevOps:</p>
  <p>Let me first shows my YAML</p>
  <pre><code># .NET Desktop
  # Build and run tests for .NET Desktop or Windows classic desktop solutions.
  # Add steps that publish symbols, save build artifacts, and more:
  # https://docs.microsoft.com/azure/devops/pipelines/apps/windows/dot-net
  
  name: $(Date:yy).$(Date:MM).$(Rev:r)
  
  trigger: 
  - master
  
  pool:
    vmImage: 'windows-latest'
  
  variables:
    solution: '**/*.sln'
    buildPlatform: 'Any CPU'
    buildConfiguration: 'Release'
  
  steps:
  - task: NuGetToolInstaller@1
  
  - task: NuGetCommand@2
    displayName: NyGetCommand Restore
    inputs:
      restoreSolution: '$(solution)'
  
  - task: VSBuild@1
    inputs:
      solution: '$(solution)'
      platform: '$(buildPlatform)'
      configuration: '$(buildConfiguration)'
  
  - task: PublishBuildArtifacts@1
    inputs:
      PathtoPublish: '$(Build.ArtifactStagingDirectory)'
      ArtifactName: 'drop'
      publishLocation: 'Container'
  </code></pre>
  <p>And now the error on last task:</p>
  <pre><code>##[warning]Directory 'D:\a\1\a' is empty. Nothing will be added to build artifact 'drop'. 
  </code></pre>
  <p>After some checking on my logs, I realized that the build (VSBuild@1) is not playing in the same folder than the publish (VSBuild@1).</p>
  <blockquote>
  <p>Build is happening in D:\a\1\s</p>
  </blockquote>
  <blockquote>
  <p>Publish is looking in D:\a\1\a</p>
  </blockquote>
  <p>Why is it working like this? Where can I control this. What are official folders. Where can I find a depp documentation about these agents and folders?</p>