Could not find a part of the path 'D:\a'.

[jsoref]

Description

Could not find a part of the path 'D:\a'.

Platforms affected

• Azure DevOps
• GitHub Actions - Standard Runners
• GitHub Actions - Larger Runners

Runner images affected

• Ubuntu 22.04
• Ubuntu 24.04
• Ubuntu Slim
• macOS 14
• macOS 14 Arm64
• macOS 15
• macOS 15 Arm64
• macOS 26 Arm64
• Windows Server 2022
• Windows Server 2025

Image version and build link

This information is not available.
https://github.com/GarnerCorp/test-charged/actions/runs/21362350661/job/61484718323?pr=88
https://github.com/GarnerCorp/test-charged/actions/runs/21362350661/job/61484718424?pr=88
https://github.com/GarnerCorp/test-charged/actions/runs/21362350661/job/61484718435?pr=88

Is it regression?

Yes. https://github.com/GarnerCorp/test-charged/actions/runs/21216371306

Expected behavior

Windows runners should start reliably and not complain about a missing D:\a

Actual behavior

2026-01-26T15:00:43.3766076Z ##[error]Could not find a part of the path 'D:\a'.

Repro steps

Trigger
https://github.com/GarnerCorp/test-charged/actions/runs/21362350661
See

[erik-bershel]

Hey @jsoref ! 👋

Thank you for bringing it to our attention. I'll work on collecting info for providing response. ⏲️

Cross-link (same reason): #13587

[eeSquared]

Hi @jsoref- thanks for identifying this! There was a regression which we are in the process of rolling back. Please let us know if you continue to experience this error.

[MoiraNix-Identiv]

As an update to the bug above: I also encountered this error on Windows Server 2022 runners this morning.

Log below:
2026-01-26T19:42:10.4498658Z ##[error]Could not find a part of the path 'D:\a'.
2026-01-26T19:42:10.4504637Z ##[debug]System.IO.DirectoryNotFoundException: Could not find a part of the path 'D:\a'.
2026-01-26T19:42:10.4505620Z ##[debug] at System.IO.FileSystem.CreateDirectory(String fullPath, Byte[] securityDescriptor)
2026-01-26T19:42:10.4506493Z ##[debug] at System.IO.Directory.CreateDirectory(String path)
2026-01-26T19:42:10.4507488Z ##[debug] at GitHub.Runner.Worker.JobRunner.RunAsync(AgentJobRequestMessage message, CancellationToken jobRequestCancellationToken)

[bmos]

I believe I am having this issue still.
https://github.com/move-coop/parsons/actions/runs/21370594083/job/61513813156?pr=1692

But some windows jobs are running. Is the build still rolling out to runners?