fix(avocet): narrow cancel except clause, clear stale cancel flags on new run

- except clause in cancel_benchmark/cancel_finetune narrowed from Exception
  to _subprocess.TimeoutExpired (C1)
- _cancelled_jobs.discard() called after registering new proc to prevent
  a stale flag from a prior run masking errors (I2)
- local `import subprocess` removed from run_benchmark and
  run_finetune_endpoint; all Popen calls updated to _subprocess.Popen (I1)
- test patch targets updated from subprocess.Popen to app.api._subprocess.Popen;
  cancelled-event tests updated to set flag in proc.wait() side-effect so
  the discard-on-new-run logic is exercised correctly

app/api.py

@@ -345,8 +345,6 @@ def get_benchmark_results():
 @app.get("/api/benchmark/run")
 def run_benchmark(include_slow: bool = False):
     """Spawn the benchmark script and stream stdout as SSE progress events."""
-    import subprocess
-
     python_bin = "/devl/miniconda3/envs/job-seeker-classifiers/bin/python"
     script = str(_ROOT / "scripts" / "benchmark_classifier.py")
     cmd = [python_bin, script, "--score", "--save"]
@@ -355,15 +353,16 @@ def run_benchmark(include_slow: bool = False):
 
     def generate():
         try:
-            proc = subprocess.Popen(
+            proc = _subprocess.Popen(
                 cmd,
-                stdout=subprocess.PIPE,
+                stdout=_subprocess.PIPE,
-                stderr=subprocess.STDOUT,
+                stderr=_subprocess.STDOUT,
                 text=True,
                 bufsize=1,
                 cwd=str(_ROOT),
             )
             _running_procs["benchmark"] = proc
+            _cancelled_jobs.discard("benchmark")  # clear any stale flag from a prior run
             try:
                 for line in proc.stdout:
                     line = line.rstrip()
@@ -421,8 +420,6 @@ def run_finetune_endpoint(
     score: list[str] = Query(default=[]),
 ):
     """Spawn finetune_classifier.py and stream stdout as SSE progress events."""
-    import subprocess
-
     python_bin = "/devl/miniconda3/envs/job-seeker-classifiers/bin/python"
     script = str(_ROOT / "scripts" / "finetune_classifier.py")
     cmd = [python_bin, script, "--model", model, "--epochs", str(epochs)]
@@ -446,16 +443,17 @@ def run_finetune_endpoint(
     def generate():
         yield f"data: {json.dumps({'type': 'progress', 'message': f'[api] Using {gpu_note} (most free VRAM)'})}\n\n"
         try:
-            proc = subprocess.Popen(
+            proc = _subprocess.Popen(
                 cmd,
-                stdout=subprocess.PIPE,
+                stdout=_subprocess.PIPE,
-                stderr=subprocess.STDOUT,
+                stderr=_subprocess.STDOUT,
                 text=True,
                 bufsize=1,
                 cwd=str(_ROOT),
                 env=proc_env,
             )
             _running_procs["finetune"] = proc
+            _cancelled_jobs.discard("finetune")  # clear any stale flag from a prior run
             try:
                 for line in proc.stdout:
                     line = line.rstrip()
@@ -491,7 +489,7 @@ def cancel_benchmark():
     proc.terminate()
     try:
         proc.wait(timeout=3)
-    except Exception:
+    except _subprocess.TimeoutExpired:
         proc.kill()
     return {"status": "cancelled"}
 
@@ -506,7 +504,7 @@ def cancel_finetune():
     proc.terminate()
     try:
         proc.wait(timeout=3)
-    except Exception:
+    except _subprocess.TimeoutExpired:
         proc.kill()
     return {"status": "cancelled"}
 

tests/test_api.py

@@ -371,7 +371,7 @@ def test_finetune_run_streams_sse_events(client):
     mock_proc.returncode = 0
     mock_proc.wait = MagicMock()
 
-    with patch("subprocess.Popen", return_value=mock_proc):
+    with patch("app.api._subprocess.Popen",return_value=mock_proc):
         r = client.get("/api/finetune/run?model=deberta-small&epochs=1")
 
     assert r.status_code == 200
@@ -387,7 +387,7 @@ def test_finetune_run_emits_complete_on_success(client):
     mock_proc.returncode = 0
     mock_proc.wait = MagicMock()
 
-    with patch("subprocess.Popen", return_value=mock_proc):
+    with patch("app.api._subprocess.Popen",return_value=mock_proc):
         r = client.get("/api/finetune/run?model=deberta-small&epochs=1")
 
     assert '{"type": "complete"}' in r.text
@@ -402,7 +402,7 @@ def test_finetune_run_emits_error_on_nonzero_exit(client):
     mock_proc.returncode = 1
     mock_proc.wait = MagicMock()
 
-    with patch("subprocess.Popen", return_value=mock_proc):
+    with patch("app.api._subprocess.Popen",return_value=mock_proc):
         r = client.get("/api/finetune/run?model=deberta-small&epochs=1")
 
     assert '"type": "error"' in r.text
@@ -422,7 +422,7 @@ def test_finetune_run_passes_score_files_to_subprocess(client):
         m.wait = MagicMock()
         return m
 
-    with patch("subprocess.Popen", side_effect=mock_popen):
+    with patch("app.api._subprocess.Popen",side_effect=mock_popen):
         client.get("/api/finetune/run?model=deberta-small&epochs=1&score=run1.jsonl&score=run2.jsonl")
 
     assert "--score" in captured_cmd
@@ -516,13 +516,17 @@ def test_finetune_run_emits_cancelled_event(client):
     mock_proc.stdout = iter([])
     mock_proc.returncode = -15  # SIGTERM
 
-    def mock_popen(cmd, **kwargs):
+    def mock_wait():
-        # Simulate cancel being called after process starts
+        # Simulate cancel being called while the process is running (after discard clears stale flag)
         api_module._cancelled_jobs.add("finetune")
+
+    mock_proc.wait = mock_wait
+
+    def mock_popen(cmd, **kwargs):
         return mock_proc
 
     try:
-        with patch("subprocess.Popen", side_effect=mock_popen):
+        with patch("app.api._subprocess.Popen",side_effect=mock_popen):
             r = client.get("/api/finetune/run?model=deberta-small&epochs=1")
         assert '{"type": "cancelled"}' in r.text
         assert '"type": "error"' not in r.text
@@ -539,12 +543,17 @@ def test_benchmark_run_emits_cancelled_event(client):
     mock_proc.stdout = iter([])
     mock_proc.returncode = -15
 
-    def mock_popen(cmd, **kwargs):
+    def mock_wait():
+        # Simulate cancel being called while the process is running (after discard clears stale flag)
         api_module._cancelled_jobs.add("benchmark")
+
+    mock_proc.wait = mock_wait
+
+    def mock_popen(cmd, **kwargs):
         return mock_proc
 
     try:
-        with patch("subprocess.Popen", side_effect=mock_popen):
+        with patch("app.api._subprocess.Popen",side_effect=mock_popen):
             r = client.get("/api/benchmark/run")
         assert '{"type": "cancelled"}' in r.text
         assert '"type": "error"' not in r.text