Fix same-head TrainerRank GPU reuse

.github/workflows/trainer-rank-gpu.yml

@@ -38,6 +38,18 @@ jobs:
         with:
           script: |
             const pull = context.payload.pull_request;
+            const identity = [
+              pull?.head?.repo?.full_name,
+              pull?.head?.ref,
+              pull?.head?.sha,
+              pull?.base?.sha,
+            ];
+            if (!identity.every(value =>
+              typeof value === 'string' && value.length > 0
+            )) {
+              core.warning('Prior GPU validation identity is incomplete.');
+              return;
+            }
             const runs = await github.rest.actions.listWorkflowRuns({
               ...context.repo,
               workflow_id: 'trainer-rank-gpu.yml',
@@ -48,9 +60,10 @@ jobs:
             });
             const candidates = runs.data.workflow_runs.filter(run =>
               run.id !== context.runId &&
+              run.head_repository?.full_name === pull.head.repo.full_name &&
+              run.head_branch === pull.head.ref &&
               run.head_sha === pull.head.sha &&
-              run.path === '.github/workflows/trainer-rank-gpu.yml' &&
-              (run.pull_requests ?? []).some(previous => previous.number === pull.number)
+              run.path === '.github/workflows/trainer-rank-gpu.yml'
             ).slice(0, 10);
             for (const run of candidates) {
               const jobs = await github.rest.actions.listJobsForWorkflowRun({

tests/unit/test_trainer_rank_gpu_workflow.py

@@ -0,0 +1,33 @@
+from pathlib import Path
+
+
+def test_ready_for_review_reuse_has_stable_source_provenance() -> None:
+    workflow = (
+        Path(__file__).parents[2] / ".github/workflows/trainer-rank-gpu.yml"
+    ).read_text()
+
+    assert "github.event.action == 'ready_for_review'" in workflow
+    assert "pull?.head?.repo?.full_name" in workflow
+    assert "pull?.head?.ref" in workflow
+    assert "pull?.head?.sha" in workflow
+    assert "pull?.base?.sha" in workflow
+    assert "identity.every(value =>" in workflow
+    assert "typeof value === 'string' && value.length > 0" in workflow
+    assert "run.head_repository?.full_name === pull.head.repo.full_name" in workflow
+    assert "run.head_branch === pull.head.ref" in workflow
+    assert "run.head_sha === pull.head.sha" in workflow
+    assert "run.path === '.github/workflows/trainer-rank-gpu.yml'" in workflow
+    assert "run.pull_requests" not in workflow
+
+
+def test_ready_for_review_reuse_requires_exact_base_artifact_and_gpu_job() -> None:
+    workflow = (
+        Path(__file__).parents[2] / ".github/workflows/trainer-rank-gpu.yml"
+    ).read_text()
+
+    assert "job.name === 'Run on 2x H200' && job.conclusion === 'success'" in workflow
+    assert "!artifact.expired" in workflow
+    assert (
+        "`trainer-rank-result-${run.id}-${run.run_attempt}-${pull.base.sha}`"
+        in workflow
+    )