chore: import upstream snapshot with attribution

doc/source/ray-observability/doc_code/ray-distributed-debugger.py

@@ -0,0 +1,30 @@
+import ray
+import sys
+
+# Add the RAY_DEBUG_POST_MORTEM=1 environment variable
+# if you want to activate post-mortem debugging
+ray.init(
+    runtime_env={
+        "env_vars": {"RAY_DEBUG_POST_MORTEM": "1"},
+    }
+)
+
+
+@ray.remote
+def my_task(x):
+    y = x * x
+    breakpoint()  # Add a breakpoint in the Ray task.
+    return y
+
+
+@ray.remote
+def post_mortem(x):
+    x += 1
+    raise Exception("An exception is raised.")
+    return x
+
+
+if len(sys.argv) == 1:
+    ray.get(my_task.remote(10))
+else:
+    ray.get(post_mortem.remote(10))