Untested: row 328 record runner and child niceness per attempt

agents/fethry/work/queue-328/BUILD.md

@@ -92,3 +92,16 @@ Finally restored exact test bytes/SHA, empty git diff --stat HEAD, empty porcela
 no own node/Chromium remaining. Scan saw only inspection Python, which exited. Slot
 returned fethry0039 while Sage rules; no test/runner modifications. Raw and normalized
 receipts retained in evidence/aborted-sage4194 with provenance and explicit EXCLUDED.md.
+
+## sage4196 priority ruling — preparation only
+
+Sage reports active ananicy-cpp (15s checks/apply_nice); no specific Python rule proven.
+Priority drift alone is no longer a stop condition and has no bearing on test validity.
+Fresh CLEAR required after Della. Begin again at attempt1, initial absolute nice19, Python-B.
+
+Only stress.py instrumentation added: a read-only100ms /proc sampler records runner and
+timeout/Node descendant pid, comm, nice and elapsed sample time for every attempt, retaining
+changes. Existing wait, timeout, verdict, phase order, mutation and restoration paths unchanged.
+No renice loop or host/rule change. Test/manifest remain identical to36668b698. Static AST
+parse only; no runner or tests executed. Stop remains fixed red, dirty tree or other unexpected
+event. Final clean checks include full git status --porcelain as well as diff --stat.

agents/fethry/work/queue-328/stress.py

@@ -8,6 +8,7 @@ from pathlib import Path
 import re
 import signal
 import subprocess
+import threading
 import time
 
 ROOT = Path(__file__).resolve().parents[4]
@@ -21,6 +22,37 @@ def digest(value):
     return hashlib.sha256(value).hexdigest()
 
 
+def sample_nice(child_pid, records, stopped):
+    """Read-only samples of the runner and timeout/Node descendants (sage-4196)."""
+    seen = set()
+    started = time.monotonic()
+    while True:
+        pending = [os.getpid(), child_pid]
+        visited = set()
+        while pending:
+            pid = pending.pop()
+            if pid in visited:
+                continue
+            visited.add(pid)
+            proc = Path('/proc') / str(pid)
+            try:
+                stat = (proc / 'stat').read_text()
+                fields = stat.rsplit(')', 1)[1].split()
+                nice = int(fields[16])  # stat field19, after pid and parenthesized comm
+                command = stat.split('(', 1)[1].rsplit(')', 1)[0]
+                key = (pid, command, nice)
+                if key not in seen:
+                    records.append({'pid': pid, 'command': command, 'nice': nice,
+                                    'seconds': round(time.monotonic() - started, 3)})
+                    seen.add(key)
+                if pid != os.getpid():
+                    pending.extend(map(int, (proc / 'task' / str(pid) / 'children').read_text().split()))
+            except (OSError, ValueError):
+                pass  # Short-lived children may exit between the read-only samples.
+        if stopped.wait(.1):
+            return
+
+
 def main():
     parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument('--clear-key', required=True, help='Sage message authorizing this test slot')
@@ -55,6 +87,9 @@ def main():
         signals = []
         with log.open('w') as stream:
             child = subprocess.Popen(command, cwd=ROOT, env=env, stdout=stream, stderr=subprocess.STDOUT, start_new_session=True)
+            nice_samples, nice_stop = [], threading.Event()
+            sampler = threading.Thread(target=sample_nice, args=(child.pid, nice_samples, nice_stop), daemon=True)
+            sampler.start()
             try:
                 code = child.wait(timeout=135)
             except subprocess.TimeoutExpired:
@@ -62,6 +97,8 @@ def main():
                 signals.append('KILL')
                 code = child.wait()
             finally:
+                nice_stop.set()
+                sampler.join()
                 try:
                     os.killpg(child.pid, signal.SIGTERM)
                     signals.append('TERM')
@@ -81,7 +118,7 @@ def main():
                 and "+   code: 'library-sync-busy'" in text and "-   code: 'library-fetch-no-grant'" in text)
         entry = {'phase': phase, 'attempt': number, 'command': command, 'TMPDIR': temporary, 'load': os.getloadavg(),
                  'exit': code, 'counts': counts, 'green': green, 'race': race, 'seconds': round(time.monotonic() - before, 3),
-                 'cleanupSignals': signals, 'TAP': log.name, 'TAPSHA256': digest(log.read_bytes())}
+                 'niceSamples': nice_samples, 'cleanupSignals': signals, 'TAP': log.name, 'TAPSHA256': digest(log.read_bytes())}
         report['runs'].append(entry)
         save()
         print(json.dumps(entry), flush=True)