Log the reason a runtime node goes down (#1368)

Co-authored-by: Jonatan Kłosko <jonatanklosko@gmail.com>

lib/livebook/session.ex

@@ -182,7 +182,6 @@ defmodule Livebook.Session do
     * `{:hydrate_bin_entries, entries}`
     * `{:operation, operation}`
     * `{:error, error}`
-    * `{:info, info}`
 
   """
   @spec subscribe(id()) :: :ok | {:error, term()}
@@ -967,8 +966,11 @@ defmodule Livebook.Session do
   end
 
   @impl true
-  def handle_info({:DOWN, ref, :process, _, _}, %{runtime_monitor_ref: ref} = state) do
-    broadcast_info(state.session_id, "runtime node terminated unexpectedly")
+  def handle_info({:DOWN, ref, :process, _, reason}, %{runtime_monitor_ref: ref} = state) do
+    broadcast_error(
+      state.session_id,
+      "runtime node terminated unexpectedly - #{Exception.format_exit(reason)}"
+    )
 
     {:noreply,
      %{state | runtime_monitor_ref: nil}
@@ -1511,10 +1513,6 @@ defmodule Livebook.Session do
     broadcast_message(session_id, {:error, error})
   end
 
-  defp broadcast_info(session_id, info) do
-    broadcast_message(session_id, {:info, info})
-  end
-
   defp broadcast_message(session_id, message) do
     Phoenix.PubSub.broadcast(Livebook.PubSub, "sessions:#{session_id}", message)
   end

lib/livebook_web/live/session_live.ex

@@ -1106,12 +1106,6 @@ defmodule LivebookWeb.SessionLive do
     {:noreply, put_flash(socket, :error, message)}
   end
 
-  def handle_info({:info, info}, socket) do
-    message = info |> to_string() |> upcase_first()
-
-    {:noreply, put_flash(socket, :info, message)}
-  end
-
   def handle_info({:hydrate_bin_entries, hydrated_entries}, socket) do
     hydrated_entries_map = Map.new(hydrated_entries, fn entry -> {entry.cell.id, entry} end)
 

test/livebook/session_test.exs

@@ -513,7 +513,7 @@ defmodule Livebook.SessionTest do
 
     assert_receive {:operation, {:set_runtime, _, runtime}}
     refute Runtime.connected?(runtime)
-    assert_receive {:info, "runtime node terminated unexpectedly"}
+    assert_receive {:error, "runtime node terminated unexpectedly - no connection"}
   end
 
   test "on user change sends an update operation subscribers", %{session: session} do