chore: mark US-005 as passing, update progress log

Author: LoCoBench Bot

ralph-gapfill-crossrepo/prd.json

@@ -77,8 +77,8 @@
         "Both tasks registered in selected_benchmark_tasks.json and crossrepo_2config.sh"
       ],
       "priority": 5,
-      "passes": false,
-      "notes": "Good candidate: K8s → client-go → apimachinery type chain. Or Istio → envoy-api → protobuf definition chain. go_to_definition with cross-repo jumps is the killer MCP feature for this."
+      "passes": true,
+      "notes": "crossrepo-chain-001: Kubernetes TypeMeta chain (k/k → k/api → k/apimachinery). crossrepo-chain-002: Envoy RouteConfiguration chain (istio → go-control-plane → data-plane-api). Both use partial credit scorer for each step in the chain. Ground truth verified via Sourcegraph."
     }
   ]
 }

ralph-gapfill-crossrepo/progress.txt

@@ -123,3 +123,40 @@
   - SG repo mapping uses the primary repo where the interface is most commonly referenced (not necessarily defined)
   - Both tasks use category=symbol_resolution (consistent with sym-001/002/003), though "interface_implementors" would be more specific
 ---
+## 2026-02-16 - US-005
+- Implemented crossrepo-chain-001 and crossrepo-chain-002: Dependency chain resolution tasks
+- Files created:
+  - benchmarks/ccb_crossrepo/crossrepo-chain-001/task.toml
+  - benchmarks/ccb_crossrepo/crossrepo-chain-001/instruction.md
+  - benchmarks/ccb_crossrepo/crossrepo-chain-001/environment/Dockerfile
+  - benchmarks/ccb_crossrepo/crossrepo-chain-001/tests/test.sh (partial credit scorer)
+  - benchmarks/ccb_crossrepo/crossrepo-chain-001/tests/ground_truth.json
+  - benchmarks/ccb_crossrepo/crossrepo-chain-002/task.toml
+  - benchmarks/ccb_crossrepo/crossrepo-chain-002/instruction.md
+  - benchmarks/ccb_crossrepo/crossrepo-chain-002/environment/Dockerfile
+  - benchmarks/ccb_crossrepo/crossrepo-chain-002/tests/test.sh (partial credit scorer)
+  - benchmarks/ccb_crossrepo/crossrepo-chain-002/tests/ground_truth.json
+- Files modified:
+  - configs/selected_benchmark_tasks.json (added 2 task entries, updated counts: 195→197 total, 8→10 crossrepo)
+  - configs/crossrepo_2config.sh (added SG repo mappings for both chain tasks)
+- crossrepo-chain-001: Kubernetes TypeMeta dependency chain
+  - 3 repos: kubernetes/kubernetes → kubernetes/api → kubernetes/apimachinery
+  - Traces TypeMeta struct from Pod usage through import chain to original definition
+  - Ground truth: 3 steps (usage at line 5465, import at line 21, definition at line 42)
+  - Partial credit scorer: each step worth 1/3 of total score, +/- 50 line tolerance
+- crossrepo-chain-002: Envoy RouteConfiguration dependency chain
+  - 3 repos: istio/istio → envoyproxy/go-control-plane → envoyproxy/data-plane-api
+  - Traces RouteConfiguration from Istio RDS generator through generated Go code to protobuf definition
+  - Ground truth: 3 steps (usage in httproute.go:115, generated struct in route.pb.go:45, proto definition in route.proto:26)
+  - Same partial credit scorer as chain-001
+- **Learnings for future iterations:**
+  - Dependency chain tasks differ from caller/implementor tasks: they trace a symbol through import chains, not find all usages
+  - Partial credit scoring is essential for chain tasks — agents may get some steps right but not all
+  - Line number tolerance (+/- 50 lines) allows for minor code changes without invalidating ground truth
+  - Kubernetes staging directory pattern means logical "3 repos" are physically subdirs in k/k monorepo — task Dockerfile clones separate repos to simulate cross-repo navigation
+  - Envoy xDS ecosystem has clearer 3-repo chain: protobuf definitions (data-plane-api) → generated Go code (go-control-plane) → consumer (istio)
+  - Both tasks use category=symbol_resolution (consistent with sym/impl tasks), difficulty=very_hard (cross-repo navigation is challenging)
+  - Test scorer uses "steps" array in ground_truth.json (not "entries" like F1 tasks) and matches by step number or position
+  - Scorer normalizes file paths (strips /workspace/ prefix) and allows missing line numbers without penalty
+  - All repos must be indexed on Sourcegraph for MCP advantage in go_to_definition cross-repo jumps
+---