2025-11-20: E2E test failures caused by GitLab Runner v18.6.0 shell executor issue

E2E test failures caused by GitLab Runner v18.6.0 shell executor issue (Severity 3)

Problem: Persistent QA test failures in the 'job_cat' job blocked deployments. The failures occurred because the job could not find a required file variable, even though it was set correctly.

Impact: Deployments to higher environments, from gprd-cny and higher, were blocked because persistent QA test failures prevented new changes from being deployed. No further deployment impact has been observed since quarantining the affected tests.

Causes: A regression in GitLab Runner 18.6.0 caused file variables that reference other variables to be incorrectly expanded, resulting in file path errors and test failures. This issue was introduced in commit 50044b81 and is tracked in Runner issue #39124.

Response strategy: We quarantined the affected QA spec file to unblock deployments. The root cause was identified and is being coordinated for a fix with the runner team.

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This ticket was created to track INC-5889, by incident.io 🔥