WinAppDriver Azure Pipelines Task stop command is flaky

We have recently integrated WinAppDriver into our builds at Accessibility Insights for Windows. We’ve been seeing periodic errors in relation to stopping WinAppDriver in our build pipeline. The YAML we use is as follows:

  - task: WinAppDriver.winappdriver-pipelines-task.winappdriver-pipelines-task.Windows Application Driver@0
    displayName: 'Stop - WinAppDriver'
    inputs:
      OperationType: Stop

This usually works as expected, but sometimes fails with:

  | ##[error]The process cannot access the file 'D:\a\_tasks\Windows Application Driver_f7c56e2a-d1f1-4cff-b5d3-a32c9516c6e0\0.0.1\winappdriverlog.txt' because it is being used by another process. |  

Full log output at end of issue.

Do you know if there is something we may be doing that causes this error? Or is it an issue with the build task itself?

  | ##[debug]Evaluating condition for step: 'Stop - WinAppDriver' |  
  | ##[debug]Evaluating: SucceededNode() |  
  | ##[debug]Evaluating SucceededNode: |  
  | ##[debug]=> True |  
  | ##[debug]Result: True |  
  | Starting: Stop - WinAppDriver |  
  | ============================================================================== |  
  | Task         : WinAppDriver |  
  | Description  : Use this extention to integrate Windows Application Driver (WinAppDriver) into your Azure Pipeline. |  
  | Version      : 0.0.1 |  
  | Author       : Microsoft |  
  | Help         : Checkout the WinAppDriver GitHub Repo to learn more - https://github.com/Microsoft/WinAppDriver |  
  | ============================================================================== |  
  | ##[debug]VstsTaskSdk 0.11.0 commit 7ff27a3e0bdd6f7b06690ae5f5b63cb84d0f23f4 |  
  | ##[debug]Entering D:\a\_tasks\Windows Application Driver_f7c56e2a-d1f1-4cff-b5d3-a32c9516c6e0\0.0.1\WADPowershell.ps1. |  
  | ##[debug]Loading resource strings from: D:\a\_tasks\Windows Application Driver_f7c56e2a-d1f1-4cff-b5d3-a32c9516c6e0\0.0.1\task.json |  
  | ##[debug]Loaded 0 strings. |  
  | ##[debug]SYSTEM_CULTURE: 'en-US' |  
  | ##[debug]INPUT_OPERATIONTYPE: 'Stop' |  
  | ##[debug]INPUT_WADARGUMENTS (empty) |  
  | ##[debug]INPUT_AGENTRESOLUTION: 'Default' |  
  | Successfully closed WinAppDriver on Agent |  
  |   |  
  | Printing WinAppDriver Console logs: |  
  |   |  
  | ##[debug]Caught exception from task script. |  
  | ##[debug]Error record: |  
  | ##[debug]Out-File : The process cannot access the file 'D:\a\_tasks\Windows Application Driver_f7c56e2a-d1f1-4cff-b5d3-a32c9516c6e0\0.0.1\winappdriverlog.txt' because it is being used by another process. |  
  | ##[debug]At D:\a\_tasks\Windows Application Driver_f7c56e2a-d1f1-4cff-b5d3-a32c9516c6e0\0.0.1\WADPowershell.ps1:41 char:2 |  
  | ##[debug]+     Out-File -Encoding Unicode -append winappdriverlog.txt |  
  | ##[debug]+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |  
  | ##[debug]    + CategoryInfo          : OpenError: (:) [Out-File], IOException |  
  | ##[debug]    + FullyQualifiedErrorId : FileOpenFailure,Microsoft.PowerShell.Commands.OutFileCommand |  
  | ##[debug] |  
  | ##[debug]Script stack trace: |  
  | ##[debug]at <ScriptBlock>, D:\a\_tasks\Windows Application Driver_f7c56e2a-d1f1-4cff-b5d3-a32c9516c6e0\0.0.1\WADPowershell.ps1: line 41 |  
  | ##[debug]at <ScriptBlock>, <No file>: line 1 |  
  | ##[debug]at <ScriptBlock>, <No file>: line 22 |  
  | ##[debug]at <ScriptBlock>, <No file>: line 18 |  
  | ##[debug]at <ScriptBlock>, <No file>: line 1 |  
  | ##[debug]Exception: |  
  | ##[debug]System.IO.IOException: The process cannot access the file 'D:\a\_tasks\Windows Application Driver_f7c56e2a-d1f1-4cff-b5d3-a32c9516c6e0\0.0.1\winappdriverlog.txt' because it is being used by another process. |  
  | ##[debug]   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) |  
  | ##[debug]   at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost) |  
  | ##[debug]   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share) |  
  | ##[debug]   at System.Management.Automation.PathUtils.MasterStreamOpen(PSCmdlet cmdlet, String filePath, Encoding resolvedEncoding, Boolean defaultEncoding, Boolean Append, Boolean Force, Boolean NoClobber, FileStream& fileStream, StreamWriter& streamWriter, FileInfo& readOnlyFileInfo, Boolean isLiteralPath) |  
  | ##[error]The process cannot access the file 'D:\a\_tasks\Windows Application Driver_f7c56e2a-d1f1-4cff-b5d3-a32c9516c6e0\0.0.1\winappdriverlog.txt' because it is being used by another process. |  
  | ##[debug]Processed: ##vso[task.logissue type=error]The process cannot access the file 'D:\a\_tasks\Windows Application Driver_f7c56e2a-d1f1-4cff-b5d3-a32c9516c6e0\0.0.1\winappdriverlog.txt' because it is being used by another process. |  
  | ##[debug]Processed: ##vso[task.complete result=Failed] |  
  | Finishing: Stop - WinAppDriver

[rubberduck203]

Closing this issue is a little premature IMO. The fix for this issue introduced a new bug that we’re also seeing. Also on a self hosted agent. My extension settings are saying 0.0.1.7 is the latest version.

[jalkire]

@hassanuz Our most recent build ran with the 0.0.2 version of the task and did not hit this issue. I will let you know if we see it again; if not, consider it fixed. Thanks! As for agent info, we were running on what I believe is a default Azure Pipelines agent using the windows-2019-vs2019 image. Its agent version was 2.154.3.