Fix frozen progress clock: heartbeat recreated on every reset_samples (previous one died during pause/resume cycles); auto-stream path appends /no_think when gateway drops chat_template_kwargs on streaming

Co-Authored-By: Claude <noreply@anthropic.com>

evalharness/model/adapter.py

@@ -203,8 +203,19 @@ class OpenAICompatible(ModelAdapter):
                     out = await self._post_stream_perf(
                         f'{self.api_base}/chat/completions', payload, headers, t0)
                 elif int(payload.get('max_tokens') or 0) > 8192:
-                    # long generation: stream and aggregate (gateway-safe)
+                    # long generation: stream and aggregate (gateway-safe).
+                    # Some gateways drop chat_template_kwargs on the STREAM
+                    # path only (non-stream honors it) -- append the /no_think
+                    # soft switch into the prompt itself as a belt-and-braces
+                    # fallback (it IS the prompt, cannot be stripped)
                     payload['stream'] = True
+                    if payload.get('chat_template_kwargs', {}).get('enable_thinking') is False:
+                        msgs = payload.get('messages') or []
+                        for m in reversed(msgs):
+                            if m.get('role') == 'user':
+                                if '/no_think' not in (m.get('content') or ''):
+                                    m['content'] = (m.get('content') or '') + ' /no_think'
+                                break
                     data = await self._post_stream_aggregate(
                         f'{self.api_base}/chat/completions', payload, headers)
                     out = self._parse(data)

evalharness/progress/rich_terminal.py

@@ -115,13 +115,18 @@ class RichTerminalProgress:
                 success=completed, failed=0, rate='0.00', inflight=0,
                 cur='0s', elapsed='0s', eta='-',
                 waiting='00:00', last_result='restored')
-            self.heartbeat_task = asyncio.create_task(self._heartbeat())
         else:
             self.progress.update(self.task_id, description=desc,
                                  total=total, completed=min(completed, total),
                                  success=completed, failed=0, rate='0.00',
                                  inflight=0, cur='0s', elapsed='0s', eta='-',
                                  last_result='restored')
+        # ALWAYS recreate the heartbeat: the previous one may have died during
+        # pause/resume cycles between benchmarks (stale reference -> silent
+        # death -> frozen clock while the spinner still animates)
+        if self.heartbeat_task is not None:
+            self.heartbeat_task.cancel()
+        self.heartbeat_task = asyncio.create_task(self._heartbeat())
 
     def set_bench_tag(self, tag: str):
         if self.disabled:
@@ -187,8 +192,11 @@ class RichTerminalProgress:
         )
 
     async def _heartbeat(self):
-        while self.task_id is not None:
+        """One tick per second: refresh elapsed + current-sample timer.
-            if self.task_id is not None:
+        Recreated on every reset_samples; must never raise or the clock
+        freezes silently."""
+        try:
+            while self.task_id is not None:
                 e = time.monotonic() - self.started
                 upd = {'elapsed': f'{int(e) // 60}m{int(e) % 60:02d}s' if e >= 60
                        else f'{int(e)}s'}
@@ -196,8 +204,13 @@ class RichTerminalProgress:
                     secs = int(time.monotonic() - self.current_started)
                     upd['cur'] = (f'{secs // 60}m{secs % 60:02d}s'
                                   if secs >= 60 else f'{secs}s')
-                self.progress.update(self.task_id, **upd)
+                try:
-            await asyncio.sleep(1)
+                    self.progress.update(self.task_id, **upd)
+                except Exception:
+                    pass  # task may have been removed mid-tick
+                await asyncio.sleep(1)
+        except asyncio.CancelledError:
+            pass
 
     def log(self, message: str):
         """Print a status line ABOVE the live bar (safe during live display).