Build times: no compatibility recipes, one recipe per line

tools/build_timings.py

@@ -3,9 +3,10 @@
 Each build-branch job records how long each of its recipes took to build (`rs <distro>
 build-ci`, in distros/<distro>/work/build_timings.jsonl) and keeps that file as an artifact
 (vinca-gha --keep-file). `robostack-bot update-build-timings` merges the last week's into
-shared/build_timings/<platform>.json, {recipe: {distro: seconds}}, and `rs <distro> gha`
-hands vinca-gha each recipe's average over the distributions: a recipe new to one
-distribution still has a time (the names are the same, ros2-<package>).
+shared/build_timings/<platform>.json, {recipe: {distro: seconds}}, one recipe per line, and
+`rs <distro> gha` hands vinca-gha each recipe's average over the distributions: a recipe new
+to one distribution still has a time (the names are the same, ros2-<package>). The
+compatibility recipes (ros-<distro>-<name>) aren't kept: they get ALIAS_SECONDS.
 
     pixi run python tools/build_timings.py   # what the bot command does
 """
@@ -25,6 +26,9 @@
 
 TIMINGS = rs.ROOT / "shared" / "build_timings"
 JOURNAL = "build_timings.jsonl"
+# a compatibility recipe (ros-<distro>-<name>) only repackages: measured median, the same
+# everywhere, so the files don't keep one per distribution
+ALIAS_SECONDS = 0.3
 
 
 def note(distro: str, recipe: str, seconds: float) -> None:
@@ -55,22 +59,34 @@ def collect(days: int = 8) -> int:
             for journal in sorted(out.rglob(JOURNAL)):
                 for line in journal.read_text().splitlines():
                     entry = json.loads(line)
+                    if entry["recipe"].startswith(f"ros-{distro}-"):
+                        continue  # a compatibility recipe: ALIAS_SECONDS
                     files.setdefault(entry["platform"], {}).setdefault(entry["recipe"], {})[distro] = entry["seconds"]
                     count += 1
     TIMINGS.mkdir(parents=True, exist_ok=True)
     for platform, recipes in files.items():
-        (TIMINGS / f"{platform}.json").write_text(json.dumps(recipes, indent=0, sort_keys=True) + "\n")
+        (TIMINGS / f"{platform}.json").write_text(dumps(recipes))
     return count
 
 
-def vinca_timings(platform: str, path: Path) -> bool:
+def dumps(recipes: dict) -> str:
+    """One recipe per line, sorted: small files, and a changed time is a one-line diff."""
+    lines = [f"{json.dumps(r)}: {json.dumps(recipes[r], sort_keys=True)}" for r in sorted(recipes)]
+    return "{\n" + ",\n".join(lines) + "\n}\n"
+
+
+def vinca_timings(distro: str, platform: str, path: Path) -> bool:
     """Write vinca-gha's --timings file for the platform: each recipe's average over the
-    distributions. False when there are no times yet."""
+    distributions, and ALIAS_SECONDS for the distribution's compatibility recipes
+    (ros-<distro>-<name>, built right after ros2-<name>). False when there are no times yet."""
     source = TIMINGS / f"{platform}.json"
     if not source.is_file():
         return False
     recipes = {r: round(statistics.fmean(by.values()), 1) for r, by in json.loads(source.read_text()).items()}
-    path.write_text(json.dumps({"recipes": recipes}) + "\n")
+    # unmeasured recipes: the median of the packages (ros2-*)
+    default = statistics.median([s for r, s in recipes.items() if r.startswith("ros2-")] or list(recipes.values()))
+    recipes.update({f"ros-{distro}-{r[len('ros2-'):]}": ALIAS_SECONDS for r in list(recipes) if r.startswith("ros2-")})
+    path.write_text(json.dumps({"recipes": recipes, "default": default}) + "\n")
     return True
 
 

tools/robostack.py

@@ -457,7 +457,7 @@ def generate_gha(distro: str, args: list[str]) -> int:
     import build_timings
 
     extra = ["--keep-file", f"distros/{distro}/work/{build_timings.JOURNAL}"]
-    if build_timings.vinca_timings(ns.platform, d / "build_timings.json"):
+    if build_timings.vinca_timings(distro, ns.platform, d / "build_timings.json"):
         extra += ["--timings", "build_timings.json"]
     # vinca-gha keeps the workflow under GitHub's size limit itself (a job budget); only
     # when even the fewest jobs the batch size allows are too many, retry with larger batches

tools/tests/test_build_timings.py

@@ -19,7 +19,7 @@ def test_collect_merges_the_runs_journals(tmp_path, monkeypatch):
     runs = [{"databaseId": 2, "headBranch": "buildbranch_jazzy_linux_64", "createdAt": "2026-10-22T02:00:00Z"},
             {"databaseId": 1, "headBranch": "buildbranch_jazzy_linux_64", "createdAt": "2026-10-22T01:00:00Z"},
             {"databaseId": 3, "headBranch": "buildbranch_lyrical_linux_64", "createdAt": "2026-10-22T03:00:00Z"}]
-    journals = {1: [("ros2-a", 10.0), ("ros2-b", 5.0)], 2: [("ros2-a", 12.0)], 3: [("ros2-a", 20.0)]}
+    journals = {1: [("ros2-a", 10.0), ("ros2-b", 5.0), ("ros-jazzy-a", 0.2)], 2: [("ros2-a", 12.0)], 3: [("ros2-a", 20.0)]}
 
     def run(cmd, **kwargs):
         if cmd[1:3] == ["run", "list"]:
@@ -32,15 +32,20 @@ def run(cmd, **kwargs):
         return subprocess.CompletedProcess(cmd, 0, b"", b"")
 
     monkeypatch.setattr(build_timings.subprocess, "run", run)
-    assert build_timings.collect() == 4
-    # the newer jazzy run wins; each distribution keeps its own time
-    assert json.loads((tmp_path / "timings" / "linux-64.json").read_text()) == {
-        "ros2-a": {"jazzy": 12.0, "lyrical": 20.0}, "ros2-b": {"jazzy": 5.0}}
+    assert build_timings.collect() == 4  # the compatibility recipe is not kept
+    # the newer jazzy run wins; each distribution keeps its own time; compatibility
+    # recipes aren't kept; one recipe per line
+    text = (tmp_path / "timings" / "linux-64.json").read_text()
+    assert json.loads(text) == {"ros2-a": {"jazzy": 12.0, "lyrical": 20.0}, "ros2-b": {"jazzy": 5.0}}
+    assert text.splitlines()[1] == '"ros2-a": {"jazzy": 12.0, "lyrical": 20.0},'
     # vinca-gha gets the average over the distributions
     out = tmp_path / "vinca.json"
-    assert build_timings.vinca_timings("linux-64", out)
-    assert json.loads(out.read_text()) == {"recipes": {"ros2-a": 16.0, "ros2-b": 5.0}}
-    assert not build_timings.vinca_timings("win-64", out)
+    assert build_timings.vinca_timings("humble", "linux-64", out)
+    assert json.loads(out.read_text()) == {
+        "recipes": {"ros2-a": 16.0, "ros2-b": 5.0, "ros-humble-a": build_timings.ALIAS_SECONDS,
+                    "ros-humble-b": build_timings.ALIAS_SECONDS},
+        "default": 10.5}
+    assert not build_timings.vinca_timings("humble", "win-64", out)
 
 
 def test_update_build_timings_command(tmp_path, monkeypatch):
@@ -84,4 +89,5 @@ def fake_run_tee(cmd, cwd):
     (tmp_path / "timings" / "linux-64.json").write_text('{"ros2-a": {"jazzy": 3.0}}\n')
     assert rs.generate_gha("jazzy", ["--platform", "linux-64"]) == 0
     assert calls[-1][calls[-1].index("--timings") + 1] == "build_timings.json"
-    assert json.loads((work / "build_timings.json").read_text()) == {"recipes": {"ros2-a": 3.0}}
+    assert json.loads((work / "build_timings.json").read_text()) == {
+        "recipes": {"ros2-a": 3.0, "ros-jazzy-a": build_timings.ALIAS_SECONDS}, "default": 3.0}