Keep Zed layer replays cohort-correct

.github/workflows/zed-cargo-product.yml

@@ -10,12 +10,12 @@ on:
         type: string
         default: ""
       base_sha:
-        description: Seed commit. Defaults to benchmark-source.env.
+        description: Seed commit. Defaults to cargo-layer-source.env.
         required: false
         type: string
         default: ""
       head_sha:
-        description: Adjacent commit built by every warm lane. Defaults to benchmark-source.env.
+        description: Adjacent commit built by every warm lane. Defaults to cargo-layer-source.env.
         required: false
         type: string
         default: ""
@@ -55,7 +55,7 @@ jobs:
           INPUT_HEAD_SHA: ${{ inputs.head_sha }}
         run: |
           set -euo pipefail
-          source benchmark-source.env
+          source cargo-layer-source.env
           echo "base_sha=${INPUT_BASE_SHA:-$ZED_BASE_SHA}" >> "$GITHUB_OUTPUT"
           echo "head_sha=${INPUT_HEAD_SHA:-$ZED_HEAD_SHA}" >> "$GITHUB_OUTPUT"
 
@@ -165,7 +165,6 @@ jobs:
           mode: cargo
           trust-policy: restore
           working-directory: upstream
-          fail-on-cache-miss: true
           fail-on-cache-error: true
           diagnostics: summary
           metadata-hints: phase=matrix-target-only-primary
@@ -317,7 +316,6 @@ jobs:
           mode: cargo
           trust-policy: restore
           working-directory: upstream
-          fail-on-cache-miss: true
           fail-on-cache-error: true
           diagnostics: summary
           metadata-hints: phase=matrix-combined-primary

README.md

@@ -11,6 +11,11 @@ lane/phase selector.
 The GitHub workflow selects those plans and leaves cache identity, target
 selection, and compiler-cache selection to the BoringCache CLI.
 
+[`cargo-layer-source.env`](cargo-layer-source.env) pins the reviewed adjacent
+source pair for that matrix independently of the continuously advancing rolling
+source. Every matrix plan tag carries the pinned head identity, so a later
+rolling sync cannot silently turn the cold seed into an older-cohort restore.
+
 The root [`.boringcache.toml`](.boringcache.toml) owns the persistent rolling
 chain. [`.github/workflows/zed-cargo-product.yml`](.github/workflows/zed-cargo-product.yml)
 owns the independent release matrix.

cargo-layer-source.env

@@ -0,0 +1,3 @@
+ZED_SOURCE_REPOSITORY=zed-industries/zed
+ZED_BASE_SHA=4e8057d74db3570b3bd419ff296eb84c35b3a5a3
+ZED_HEAD_SHA=d4010e91ccc9635853698af160f15bb479a484d0

plans/cold/primary/.boringcache.toml

@@ -1,21 +1,21 @@
 workspace = "boringcache/benchmark-zed"
 
 [entries.cargo-registry]
-tag = "zed-cargo-layers-1181-d4010e9-registry"
+tag = "zed-cargo-layers-1181-d4010e9-r4-registry"
 
 [entries.cargo-git]
-tag = "zed-cargo-layers-1181-d4010e9-git"
+tag = "zed-cargo-layers-1181-d4010e9-r4-git"
 
 [entries.zed-target]
 kind = "cargo-target"
-tag = "zed-cargo-layers-1181-d4010e9-target"
+tag = "zed-cargo-layers-1181-d4010e9-r4-target"
 path = "target"
 
 [profiles.cargo-product]
 entries = ["cargo-registry", "cargo-git", "zed-target"]
 
 [adapters.sccache]
-tag = "zed-cargo-layers-1181-d4010e9-sccache"
+tag = "zed-cargo-layers-1181-d4010e9-r4-sccache"
 no-git = true
 metadata-hints = ["benchmark=zed-cargo-layers", "layer=compiler"]
 

plans/cold/remote-server/.boringcache.toml

@@ -1,21 +1,21 @@
 workspace = "boringcache/benchmark-zed"
 
 [entries.cargo-registry]
-tag = "zed-cargo-layers-1181-d4010e9-registry"
+tag = "zed-cargo-layers-1181-d4010e9-r4-registry"
 
 [entries.cargo-git]
-tag = "zed-cargo-layers-1181-d4010e9-git"
+tag = "zed-cargo-layers-1181-d4010e9-r4-git"
 
 [entries.zed-target]
 kind = "cargo-target"
-tag = "zed-cargo-layers-1181-d4010e9-target"
+tag = "zed-cargo-layers-1181-d4010e9-r4-target"
 path = "target"
 
 [profiles.cargo-product]
 entries = ["cargo-registry", "cargo-git", "zed-target"]
 
 [adapters.sccache]
-tag = "zed-cargo-layers-1181-d4010e9-sccache"
+tag = "zed-cargo-layers-1181-d4010e9-r4-sccache"
 no-git = true
 metadata-hints = ["benchmark=zed-cargo-layers", "layer=compiler"]
 

plans/combined/primary/.boringcache.toml

@@ -1,21 +1,21 @@
 workspace = "boringcache/benchmark-zed"
 
 [entries.cargo-registry]
-tag = "zed-cargo-layers-1181-d4010e9-registry"
+tag = "zed-cargo-layers-1181-d4010e9-r4-registry"
 
 [entries.cargo-git]
-tag = "zed-cargo-layers-1181-d4010e9-git"
+tag = "zed-cargo-layers-1181-d4010e9-r4-git"
 
 [entries.zed-target]
 kind = "cargo-target"
-tag = "zed-cargo-layers-1181-d4010e9-target"
+tag = "zed-cargo-layers-1181-d4010e9-r4-target"
 path = "target"
 
 [profiles.cargo-product]
 entries = ["cargo-registry", "cargo-git", "zed-target"]
 
 [adapters.sccache]
-tag = "zed-cargo-layers-1181-d4010e9-sccache"
+tag = "zed-cargo-layers-1181-d4010e9-r4-sccache"
 no-git = true
 metadata-hints = ["benchmark=zed-cargo-layers", "layer=compiler"]
 

plans/combined/remote-server/.boringcache.toml

@@ -1,21 +1,21 @@
 workspace = "boringcache/benchmark-zed"
 
 [entries.cargo-registry]
-tag = "zed-cargo-layers-1181-d4010e9-registry"
+tag = "zed-cargo-layers-1181-d4010e9-r4-registry"
 
 [entries.cargo-git]
-tag = "zed-cargo-layers-1181-d4010e9-git"
+tag = "zed-cargo-layers-1181-d4010e9-r4-git"
 
 [entries.zed-target]
 kind = "cargo-target"
-tag = "zed-cargo-layers-1181-d4010e9-target"
+tag = "zed-cargo-layers-1181-d4010e9-r4-target"
 path = "target"
 
 [profiles.cargo-product]
 entries = ["cargo-registry", "cargo-git", "zed-target"]
 
 [adapters.sccache]
-tag = "zed-cargo-layers-1181-d4010e9-sccache"
+tag = "zed-cargo-layers-1181-d4010e9-r4-sccache"
 no-git = true
 metadata-hints = ["benchmark=zed-cargo-layers", "layer=compiler"]
 

plans/sccache-only/primary/.boringcache.toml

@@ -1,21 +1,21 @@
 workspace = "boringcache/benchmark-zed"
 
 [entries.cargo-registry]
-tag = "zed-cargo-layers-1181-d4010e9-registry"
+tag = "zed-cargo-layers-1181-d4010e9-r4-registry"
 
 [entries.cargo-git]
-tag = "zed-cargo-layers-1181-d4010e9-git"
+tag = "zed-cargo-layers-1181-d4010e9-r4-git"
 
 [entries.zed-target]
 kind = "cargo-target"
-tag = "zed-cargo-layers-1181-d4010e9-target"
+tag = "zed-cargo-layers-1181-d4010e9-r4-target"
 path = "target"
 
 [profiles.cargo-product]
 entries = ["cargo-registry", "cargo-git"]
 
 [adapters.sccache]
-tag = "zed-cargo-layers-1181-d4010e9-sccache"
+tag = "zed-cargo-layers-1181-d4010e9-r4-sccache"
 no-git = true
 metadata-hints = ["benchmark=zed-cargo-layers", "layer=compiler"]
 

plans/sccache-only/remote-server/.boringcache.toml

@@ -1,21 +1,21 @@
 workspace = "boringcache/benchmark-zed"
 
 [entries.cargo-registry]
-tag = "zed-cargo-layers-1181-d4010e9-registry"
+tag = "zed-cargo-layers-1181-d4010e9-r4-registry"
 
 [entries.cargo-git]
-tag = "zed-cargo-layers-1181-d4010e9-git"
+tag = "zed-cargo-layers-1181-d4010e9-r4-git"
 
 [entries.zed-target]
 kind = "cargo-target"
-tag = "zed-cargo-layers-1181-d4010e9-target"
+tag = "zed-cargo-layers-1181-d4010e9-r4-target"
 path = "target"
 
 [profiles.cargo-product]
 entries = ["cargo-registry", "cargo-git"]
 
 [adapters.sccache]
-tag = "zed-cargo-layers-1181-d4010e9-sccache"
+tag = "zed-cargo-layers-1181-d4010e9-r4-sccache"
 no-git = true
 metadata-hints = ["benchmark=zed-cargo-layers", "layer=compiler"]
 

plans/target-only/primary/.boringcache.toml

@@ -1,14 +1,14 @@
 workspace = "boringcache/benchmark-zed"
 
 [entries.cargo-registry]
-tag = "zed-cargo-layers-1181-d4010e9-registry"
+tag = "zed-cargo-layers-1181-d4010e9-r4-registry"
 
 [entries.cargo-git]
-tag = "zed-cargo-layers-1181-d4010e9-git"
+tag = "zed-cargo-layers-1181-d4010e9-r4-git"
 
 [entries.zed-target]
 kind = "cargo-target"
-tag = "zed-cargo-layers-1181-d4010e9-target"
+tag = "zed-cargo-layers-1181-d4010e9-r4-target"
 path = "target"
 
 [profiles.cargo-product]

plans/target-only/remote-server/.boringcache.toml

@@ -1,14 +1,14 @@
 workspace = "boringcache/benchmark-zed"
 
 [entries.cargo-registry]
-tag = "zed-cargo-layers-1181-d4010e9-registry"
+tag = "zed-cargo-layers-1181-d4010e9-r4-registry"
 
 [entries.cargo-git]
-tag = "zed-cargo-layers-1181-d4010e9-git"
+tag = "zed-cargo-layers-1181-d4010e9-r4-git"
 
 [entries.zed-target]
 kind = "cargo-target"
-tag = "zed-cargo-layers-1181-d4010e9-target"
+tag = "zed-cargo-layers-1181-d4010e9-r4-target"
 path = "target"
 
 [profiles.cargo-product]

scripts/summarize-cargo-evidence.py

@@ -19,7 +19,8 @@ def summarize(label: str, evidence_path: Path) -> str:
     evidence = json.loads(evidence_path.read_text())
     phase = evidence.get("phases", {}).get("restore", {})
     mode = phase.get("mode_evidence", {})
-    native = mode.get("native_tool", {})
+    native = mode.get("native_tool") or {}
+    compiler_cache = mode.get("cargo_cache", {}).get("compiler_cache")
 
     requests = native.get("compile_requests")
     executed = native.get("compile_requests_executed")
@@ -35,6 +36,8 @@ def summarize(label: str, evidence_path: Path) -> str:
         lines.append(f"  - elapsed: {elapsed:.0f}s")
     if target_hit is not None:
         lines.append(f"  - target snapshot restored: `{target_hit}`")
+    if compiler_cache == "none":
+        lines.append("  - compiler cache: disabled")
     if requests is not None:
         lines.append(
             f"  - Cargo units compiled: {executed if executed is not None else requests}"

scripts/verify-zed-release-recipe.py

@@ -115,6 +115,8 @@ def verify_upstream(upstream: Path, contract: dict[str, str]) -> None:
 
 
 def verify_plans() -> None:
+    source = read_settings(ROOT / "cargo-layer-source.env")
+    cohort = source["ZED_HEAD_SHA"][:7]
     target_tags: set[str] = set()
     compiler_tags: set[str] = set()
     dependency_tag_pairs: set[tuple[str, str]] = set()
@@ -142,6 +144,11 @@ def verify_plans() -> None:
             require(cargo["no-git"] is True, f"{path} must use stable reviewed tags")
 
             config_entries = plan["entries"]
+            for entry in config_entries.values():
+                require(
+                    cohort in entry["tag"],
+                    f"{path} does not carry the pinned layer-source identity",
+                )
             target_tags.add(config_entries["zed-target"]["tag"])
             dependency_tag_pairs.add(
                 (
@@ -155,6 +162,10 @@ def verify_plans() -> None:
                     f"{path} must give sccache an independent identity",
                 )
                 compiler_tags.add(plan["adapters"]["sccache"]["tag"])
+                require(
+                    cohort in plan["adapters"]["sccache"]["tag"],
+                    f"{path} compiler tag does not carry the pinned layer-source identity",
+                )
             else:
                 require(
                     "sccache" not in plan["adapters"],
@@ -178,6 +189,10 @@ def verify_workflows() -> None:
 
     require("scope-boringcache-run" not in all_workflows, "Workflows must not rewrite tags")
     require("mode: sccache" not in all_workflows, "Cargo owns the composed lifecycle")
+    require(
+        "source cargo-layer-source.env" in matrix,
+        "The layer matrix must not follow the moving rolling source",
+    )
     require(
         "boringcache/one@ab52a39d3d7358c22b359a6ffbf86cf74be9bf56" in matrix,
         "The matrix must use released One 1.18.1",
@@ -210,7 +225,7 @@ def verify_workflows() -> None:
 
 def verify(upstream: Path) -> str:
     contract = read_settings(ROOT / "scripts/zed-release-recipe.env")
-    source = read_settings(ROOT / "benchmark-source.env")
+    source = read_settings(ROOT / "cargo-layer-source.env")
     verify_upstream(upstream, contract)
     verify_plans()
     verify_workflows()

test/test_cargo_product.py

@@ -91,6 +91,7 @@ def test_action_selects_plans_but_does_not_plan_layers(self):
         self.assertNotIn("scope-boringcache-run", workflow_text)
         self.assertNotIn("mode: sccache", workflow_text)
         self.assertNotIn("sed -i", workflow_text)
+        self.assertNotIn("fail-on-cache-miss", matrix)
         self.assertNotIn("cache_scope:", rolling)
         self.assertEqual(matrix.count("mode: cargo"), 8)
         self.assertIn("inputs.cli_version", matrix)
@@ -129,6 +130,25 @@ def test_source_pair_matches_the_pinned_submodule(self):
 
         self.assertEqual(source["ZED_HEAD_SHA"], head)
 
+    def test_layer_matrix_owns_a_fixed_source_cohort(self):
+        source = dict(
+            line.split("=", 1)
+            for line in (ROOT / "cargo-layer-source.env").read_text().splitlines()
+        )
+        cohort = source["ZED_HEAD_SHA"][:7]
+        matrix = (WORKFLOWS / "zed-cargo-product.yml").read_text()
+
+        self.assertNotEqual(source["ZED_BASE_SHA"], source["ZED_HEAD_SHA"])
+        self.assertIn("source cargo-layer-source.env", matrix)
+        self.assertNotIn("source benchmark-source.env", matrix)
+        for path in sorted((ROOT / "plans").glob("*/*/.boringcache.toml")):
+            plan = tomllib.loads(path.read_text())
+            for entry in plan["entries"].values():
+                self.assertIn(cohort, entry["tag"])
+            sccache = plan["adapters"].get("sccache")
+            if sccache:
+                self.assertIn(cohort, sccache["tag"])
+
     def test_release_recipe_and_layer_contract(self):
         subprocess.run(
             [sys.executable, str(ROOT / "scripts/verify-zed-release-recipe.py"), "upstream"],
@@ -172,6 +192,37 @@ def test_native_hit_rate_is_already_a_percentage(self):
         self.assertIn("96.0% hit rate", result.stdout)
         self.assertNotIn("9600", result.stdout)
 
+    def test_report_handles_a_disabled_compiler_cache(self):
+        evidence = {
+            "phases": {
+                "restore": {
+                    "mode_evidence": {
+                        "elapsed_seconds": 12.4,
+                        "target_cache_hit": True,
+                        "native_tool": None,
+                        "cargo_cache": {"compiler_cache": "none"},
+                    }
+                }
+            }
+        }
+        with tempfile.TemporaryDirectory() as directory:
+            path = Path(directory) / "evidence.json"
+            path.write_text(json.dumps(evidence))
+            result = subprocess.run(
+                [
+                    sys.executable,
+                    str(ROOT / "scripts/summarize-cargo-evidence.py"),
+                    "target-only",
+                    str(path),
+                ],
+                check=True,
+                text=True,
+                capture_output=True,
+            )
+
+        self.assertIn("target snapshot restored: `True`", result.stdout)
+        self.assertIn("compiler cache: disabled", result.stdout)
+
 
 if __name__ == "__main__":
     unittest.main()