Do not purge on recompile if IEx is not running, closes #14260

Author: josevalim

lib/iex/lib/iex/mix_listener.ex

@@ -12,10 +12,18 @@ defmodule IEx.MixListener do
 
   @doc """
   Unloads all modules invalidated by external compilations.
+
+  Returns `:noop` if there is no module to purge or if
+  the listener is not running (it may happen when connecting
+  via --remsh to a node that was started without IEx).
   """
   @spec purge :: :ok | :noop
   def purge do
-    GenServer.call(@name, :purge, :infinity)
+    if Process.whereis(@name) do
+      GenServer.call(@name, :purge, :infinity)
+    else
+      :noop
+    end
   end
 
   @impl true