gh-142654: show the clear error message when sampling on an unknown PID

Lib/profiling/sampling/sample.py

@@ -34,19 +34,22 @@ def __init__(self, pid, sample_interval_usec, all_threads, *, mode=PROFILING_MOD
         self.all_threads = all_threads
         self.mode = mode  # Store mode for later use
         self.collect_stats = collect_stats
-        if _FREE_THREADED_BUILD:
-            self.unwinder = _remote_debugging.RemoteUnwinder(
-                self.pid, all_threads=self.all_threads, mode=mode, native=native, gc=gc,
-                opcodes=opcodes, skip_non_matching_threads=skip_non_matching_threads,
-                cache_frames=True, stats=collect_stats
-            )
-        else:
-            only_active_threads = bool(self.all_threads)
-            self.unwinder = _remote_debugging.RemoteUnwinder(
-                self.pid, only_active_thread=only_active_threads, mode=mode, native=native, gc=gc,
-                opcodes=opcodes, skip_non_matching_threads=skip_non_matching_threads,
-                cache_frames=True, stats=collect_stats
-            )
+        try:
+            if _FREE_THREADED_BUILD:
+                self.unwinder = _remote_debugging.RemoteUnwinder(
+                    self.pid, all_threads=self.all_threads, mode=mode, native=native, gc=gc,
+                    opcodes=opcodes, skip_non_matching_threads=skip_non_matching_threads,
+                    cache_frames=True, stats=collect_stats
+                )
+            else:
+                only_active_threads = bool(self.all_threads)
+                self.unwinder = _remote_debugging.RemoteUnwinder(
+                    self.pid, only_active_thread=only_active_threads, mode=mode, native=native, gc=gc,
+                    opcodes=opcodes, skip_non_matching_threads=skip_non_matching_threads,
+                    cache_frames=True, stats=collect_stats
+                )
+        except Exception as err:
+            raise SystemExit(err)
         # Track sample intervals and total sample count
         self.sample_intervals = deque(maxlen=100)
         self.total_samples = 0

Lib/test/test_profiling/test_sampling_profiler/test_integration.py

@@ -635,7 +635,7 @@ def test_sample_target_module(self):
 )
 class TestSampleProfilerErrorHandling(unittest.TestCase):
     def test_invalid_pid(self):
-        with self.assertRaises((OSError, RuntimeError)):
+        with self.assertRaises(SystemExit):
             collector = PstatsCollector(sample_interval_usec=100, skip_idle=False)
             profiling.sampling.sample.sample(-1, collector, duration_sec=1)
 

Misc/NEWS.d/next/Library/2025-12-13-10-34-59.gh-issue-142654.fmm974.rst

@@ -0,0 +1,2 @@
+Show the clearer error message when using ``profiling.sampling`` on an
+unknown PID.