Summary

The "Validate Signing" task in internal unified-build pipeline runs out of disk space on Linux and Mac validation legs, causing builds to report partiallySucceeded. This has been recurring on main and release/10.0.1xx branches for at least 2 days.

Error

/mnt/vss/_work/1/s/eng/signing-validation.proj(20,7): error : Signing validation failed: No space left on device

Affected Builds

Analysis

The signing-validation task iterates over all per-vertical artifact manifests and unpacks them for sign-check. With the growing number of verticals (30+ manifests observed in build 2926555 logs), the aggregate disk consumption exceeds the available space on the agent.

The failure occurs in the "Validate Signing - Linux" job, suggesting the issue is systematic rather than one-off.

Impact

• Every internal rolling build on release/10.0.1xx reports partiallySucceeded
• Internal main builds are also affected
• The partiallySucceeded status masks real failures and makes pipeline health assessment unreliable

Possible Mitigations

• Use larger disk agents for signing validation jobs
• Stream/validate manifests incrementally instead of unpacking all at once
• Clean up between vertical validations

/cc @dotnet/dnceng