The VSTS\TFS 2017 Release definition fails to create Release artifact directory at 'C:\Agents\DA_CID22\r1\a' - azure-devops

Question

Lately I have been facing this error for one of my release definition and I am not able to figure it out why is this happening.
I tried manually deleting the folders inside the r1 directory but it fails to delete the 'a' folder i.e. artifact directory and says the folder or file in it is open in another program. But its shocking that the 'a' folder is empty and don't even have a hidden files and folders in it.
As a work around, to make the release successfully get deployed I have to restart my server each time whenever I want a new release to be deployed. Which is really very annoying.
Below is the complete error that I get on the Release definition summary.
Errors (2)
 Downloading artifacts failed:
Microsoft.VisualStudio.Services.Agent.Worker.Release.Artifacts.ArtifactDirectoryCreationFailedException:
Failed to create Release artifact directory 'C:\Agents\DA_CID22\r1\a'.
---> System.IO.IOException: The process cannot access the file '\?\C:\Agents\DA_CID22\r1\a' because it is being used by another
process. at System.IO.Win32FileSystem.RemoveDirectoryHelper(String
fullPath, Boolean recursive, Boolean throwOnTopLevelDirectoryNotFound)
at System.IO.Win32FileSystem.RemoveDirectory(String fullPath, Boolean
recursive) at
Microsoft.VisualStudio.Services.Agent.Util.IOUtil.DeleteDirectory(String
path, Boolean contentsOnly, Boolean continueOnContentDeleteError,
CancellationToken cancellationToken) at
Microsoft.VisualStudio.Services.Agent.Worker.Release.ReleaseFileSystemManager.EnsureEmptyDirectory(String
directoryPath, CancellationToken cancellationToken) --- End of inner
exception stack trace --- at
Microsoft.VisualStudio.Services.Agent.Worker.Release.ReleaseFileSystemManager.EnsureEmptyDirectory(String
directoryPath, CancellationToken cancellationToken) at
Microsoft.VisualStudio.Services.Agent.Worker.Release.RetryExecutor.Execute(Action
action) at
Microsoft.VisualStudio.Services.Agent.Worker.Release.ReleaseJobExtension.CreateArtifactsFolder(IExecutionContext
executionContext, String artifactsWorkingFolder) at
Microsoft.VisualStudio.Services.Agent.Worker.Release.ReleaseJobExtension.d__34.MoveNext()
--- End of stack trace from previous location where exception was thrown --- at
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task
task) at
Microsoft.VisualStudio.Services.Agent.Worker.Release.ReleaseJobExtension.d__31.MoveNext()
 Failed to create Release artifact directory
'C:\Agents\DA_CID22\r1\a'.
Any help or advice would be really helpful.

Answer 1

This happens from time to time...I spent days trying to figure out with no easy solution (all the ones you have tried, I tried myself) but for restarting the private agent. My conclusion is that somehow the agent process got hung with the artifact Windows folder. You can see that with programs like https://lockhunter.com/. There's not an easy solution here...Sometimes you must kill the culprit process which not ended correctly freeing that file, or if you are lucky releasing the file handle to that file with a tool like said before...