Using XAML UpgradeTemplate with TFS 2015 \ 2017 - xaml

Question

I ran into this issue upgrading from TFS 2013 to 2017. If you are still using the UpgradeTemplate.xaml to run old TFS 2005\2008 style MSBuild Team Builds (TFSBuild.proj) you will find that they do not work with the TFS 2015 or 2017 XAML build agent.
You will get this error when running the build due to some breaking changes that were introduced in the core assemblies. XAML builds have been deprecated for some time... and the old MSBuild based Team Builds are waaaayyyyy out of support. So Microsoft (rightfully) doesn't care.
But is there a way to get these builds working in TFS 2015\2017? It would be a big waste of time to convert these over to using XAML builds only to then convert them to the new build engine after upgrading to TFS 2017.
C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\TeamBuild\Microsoft.TeamFoundation.Build.targets (957): The following errors were encountered while processing the workflow tree:
'VisualBasicValue<LabelChildOption>': Compiler error(s) encountered processing expression "Microsoft.TeamFoundation.VersionControl.Client.LabelChildOption.Fail".
'LabelChildOption' is ambiguous in the namespace 'Microsoft.TeamFoundation.VersionControl.Client'.
'VisualBasicValue<RecursionType>': Compiler error(s) encountered processing expression "Microsoft.TeamFoundation.VersionControl.Client.RecursionType.Full".
'RecursionType' is ambiguous in the namespace 'Microsoft.TeamFoundation.VersionControl.Client'.
C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\TeamBuild\Microsoft.TeamFoundation.Build.targets (957): The "Label" task failed unexpectedly.
System.Activities.InvalidWorkflowException: The following errors were encountered while processing the workflow tree:
'VisualBasicValue<LabelChildOption>': Compiler error(s) encountered processing expression "Microsoft.TeamFoundation.VersionControl.Client.LabelChildOption.Fail".
'LabelChildOption' is ambiguous in the namespace 'Microsoft.TeamFoundation.VersionControl.Client'.
'VisualBasicValue<RecursionType>': Compiler error(s) encountered processing expression "Microsoft.TeamFoundation.VersionControl.Client.RecursionType.Full".
'RecursionType' is ambiguous in the namespace 'Microsoft.TeamFoundation.VersionControl.Client'.
at System.Activities.Hosting.WorkflowInstance.ValidateWorkflow(WorkflowInstanceExtensionManager extensionManager)
at System.Activities.Hosting.WorkflowInstance.RegisterExtensionManager(WorkflowInstanceExtensionManager extensionManager)
at System.Activities.WorkflowApplication.EnsureInitialized()
at System.Activities.WorkflowApplication.RunInstance(WorkflowApplication instance)
at System.Activities.WorkflowApplication.Invoke(Activity activity, IDictionary`2 inputs, WorkflowInstanceExtensionManager extensions, TimeSpan timeout)
at System.Activities.WorkflowInvoker.Invoke(Activity workflow, IDictionary`2 inputs, TimeSpan timeout, WorkflowInstanceExtensionManager extensions)
at Microsoft.TeamFoundation.Build.Tasks.WorkflowTask.ExecuteInternal()
at Microsoft.TeamFoundation.Build.Tasks.Task.Execute()
at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext()

Answer 1

You can work around this error if you don’t care about labeling your code as part of the build process or updating associated work items. In my case I was still using the UpgradeTemplate as a convenient way of performing a check-in based “Get-Latest” of source code in TFVC to the builds folder on the build machine… not really a “build” at all. So this was A-OK.
Set these two properties to true in your TFSBuild.proj
This will cause MSBuild to skip execution of the CoreLabel and the CoreGetChangesetsAndUpdateWorkItems targets. CoreLabel is the one which loads the task that is failing the build... and CoreGetChangesetsAndUpdateWorkItems needs the label to exist or it will also fail.
I found these properties by digging through the old C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\TeamBuild\Microsoft.TeamFoundation.Build.targets - which is the team build script that shipped with TFS 2005 \ 2008.
<SkipLabel>true</SkipLabel>
<SkipGetChangesetsAndUpdateWorkItems>true</SkipGetChangesetsAndUpdateWorkItems>