The Get PR base branch step in Conformance EKS fails on all ariane-scheduled nightly dispatches for branches using ariane-scheduled workflow_dispatch instead of github scheduled runs. It passes the branch name with dots replaced by hyphens v1-19 as inputs.PR-number. The step then runs gh pr view v1-19 which finds no matching pull request and exits with code 1. All downstream EKS installation and connectivity test steps are skipped, so no actual EKS testing occurs on v1.19 nightly runs.

Run BASE_BRANCH=$(gh pr view v1-19 --json baseRefName -q .baseRefName)
no pull requests found for branch "v1-19"

It's defined here: https://github.com/cilium/cilium/blob/main/.github/workflows/conformance-eks.yaml#L301

This condition assumes that workflow_dispatch will always be done against a PR, but that assumption isn't correct as it's also used for stable branches schedule runs: https://github.com/cilium/cilium/blob/main/.github/workflows/ariane-scheduled.yaml

Failures:
— https://github.com/cilium/cilium/actions/runs/23349277828
— https://github.com/cilium/cilium/actions/runs/23328178984
— https://github.com/cilium/cilium/actions/runs/23317045747
— https://github.com/cilium/cilium/actions/runs/23302120096
— https://github.com/cilium/cilium/actions/runs/23252638140