[BUG]: Sparse checkout feature leads to failures when reusing agents

[PaulVrugt]

What happened?

Since #4325 was merged, we are experimenting with using this feature in our pipelines.

We are using private agents (currently using a vmss) and we reuse agents for multiple jobs (so we don't use a freshly provisioned agent for each job) for performance and caching reasons.

However, once we run a job on an agent that previously ran a job with a sparse checkout, the checkout task of the agent doesn't do a full checkout anymore. It seems that git isn't aware of the fact the existing state is in a sparse checkout state, so it doesn't check out all files. This leads to random failures because of missing files in the repository.

Versions

4.251.0

Environment type (Please select at least one enviroment where you face this issue)

• Self-Hosted
• Microsoft Hosted
• VMSS Pool
• Container

Azure DevOps Server type

dev.azure.com (formerly visualstudio.com)

Azure DevOps Server Version (if applicable)

No response

Operation system

No response

Version controll system

No response

Relevant log output

[Penguinwizzard]

I suspect this may be fixed by 6bee6b7 - it moved the sparse checkout config before the new fetch/checkout, so it should become non-sparse in that flow.