Azure Devops - UI tests fail to run on Self hosted agent

Question

While trying to run Coded UI tests on Azure self hosted agent, getting the below error

Agent machine has VS test platform installed and also contains VS2017 build tools to run Coded ui tests.

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at Microsoft.VisualStudio.TestPlatform.Core.ITestRunnerService.InitializeConnection(IEnumerable`1 pathToAdditionalExtensions, Boolean loadOnlyWellKnownExtensions)
   at Microsoft.VisualStudio.TestPlatform.Client.TestRunnerServiceProxy.InitializeConnection(IEnumerable`1 pathToAdditionalExtensions, Boolean loadOnlyWellKnownExtensions)
   at Microsoft.VisualStudio.TestPlatform.Client.TestRunnerServiceClient.TestConnection(Binding binding, EndpointAddress address, TestRunnerServiceProxy& proxy, Exception& exceptionDuringConnection)
   --- End of inner exception stack trace ---
   at Microsoft.VisualStudio.TestPlatform.Client.TestRunnerServiceClient.InitializeProxy()
   at Microsoft.VisualStudio.TestPlatform.Client.TestRunnerServiceClient.Initialize_NoLock(Boolean forceX86Discoverer)
   at Microsoft.VisualStudio.TestPlatform.Client.TestRunnerServiceClient.EnsureInitialized(Boolean forceX86Discoverer, Boolean shouldCheckForRelaunch)
   at Microsoft.VisualStudio.TestPlatform.Client.TestRunnerServiceClient.InvokeTestRunnerServiceAction(Boolean forceX86Discoverer, Action`1 action)
   at Microsoft.VisualStudio.TestPlatform.Client.TestRunnerServiceClient.DiscoverTests(IEnumerable`1 sources, String settings, Int64 frequencyOfDiscoveredTestEvent, ITestCaseDiscoveryLog testCaseDiscoveryLog, TimeSpan discoveredTestEventTimeout)
   at Microsoft.VisualStudio.TestPlatform.Client.Rocksteady.RocksteadyDiscoveryManager.DiscoverTestsForTestRun(DiscoveryCriteria discoveryCriteria, ITestDiscoveryEventsHandler eventHandler)
   at Microsoft.VisualStudio.TestPlatform.Client.DiscoveryRequest.Microsoft.VisualStudio.TestPlatform.ObjectModel.Client.IDiscoveryRequest.DiscoverAsync()
   at Microsoft.VisualStudio.TestService.VstestAdapter.DiscoverTests.PerformDiscovery(TestAutomationRunSlice sliceDetails, IAddTestCasesToTcmRunHandler addTestCasesToTcmRunHandler, ExecutionStateContext stateModelContext)
   at Microsoft.VisualStudio.TestService.VstestAdapter.Execution.FetchPreviousPhaseData(ExecutionStateContext stateModelContext)
   at Microsoft.VisualStudio.TestService.VstestAdapter.ExecutionAndPublish.Run(ExecutionStateContext stateModelContext, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()<---

##[error]TestExecution encountered unexpected failures System.AggregateException: One or more errors occurred. ---> Microsoft.VisualStudio.TestPlatform.Common.TestRunner.TestPlatformException: Failed to initialize client proxy: could not connect to test process vstest.discoveryengine.x86.exe. ---> System.ServiceModel.EndpointNotFoundException: There was no endpoint listening at net.pipe://machineA/vstest.discoveryengine/15248 that could accept the message. This is often caused by an incorrect address or SOAP action. See InnerException, if present, for more details.

Specifically, the task that is failing is the Visual Studio Test task (VSTest@2). Immediately before that step, there is a Visual Studio test platform installer task (VisualStudioTestPlatformInstaller@1), which is set up to target the latest test platform available from nuget.

The CodedUI tests are being built using VS2017.

These are the yaml tasks:

  - task: VisualStudioTestPlatformInstaller@1
    displayName: 'Visual Studio Test Platform Installer'
    inputs:
      versionSelector: latestStable


  - task: VSTest@2
    displayName: 'CodedUI Tests'
    inputs:
      testSelector: 'testPlan'
      testPlan: '8369'
      testSuite: '8373'
      testConfiguration: '13'
      searchFolder: 'C:\Testing\bin\Tests'
      uiTests: true
      runSettingsFile: 'C:\Testing\bin\Tests\Solution Items\OurTestSettings.testsettings'
      runTestsInIsolation: true
      testRunTitle: 'Nightly Tests'

Answer 1

Changed cmd.exe to run in elevated privileges which always launches Agent.Listener as administrator solved the issue.