<Target Name="MyTarget">
  <BuildStep 
      Name="MyBuildStepName" 
      Message="My message for %(ConfigurationToBuild.FlavorToBuild)"
      TeamFoundationServerUrl="$(TeamFoundationServerUrl)"
      BuildUri="$(BuildURI)"
      Condition="'$(IsDesktopBuild)'!='true'">
    <Output TaskParameter="Id" PropertyName="StepId" />
  </BuildStep>

  <!-- DO SOMETHING THAT CAN FAIL -->

  <BuildStep
      Id="$(StepId)"
      Name="MyBuildStepName"
      Status="Succeeded" 
      TeamFoundationServerUrl="$(TeamFoundationServerUrl)"
      BuildUri="$(BuildURI)"
      Condition="'$(IsDesktopBuild)'!='true'" />
  <OnError ExecuteTargets="MyBuildStepError" />
</Target>

<Target Name="MyBuildStepError">
  <BuildStep
    Id="$(StepId)"
    Name="MyBuildStepName"
    Status="Failed"
    TeamFoundationServerUrl="$(TeamFoundationServerUrl)"
    BuildUri="$(BuildURI)"
    Condition="'$(IsDesktopBuild)'!='true'" />
</Target>

Custom Build Steps for MSBuild

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