Avoid purging non-loaded modules

Author: josevalim

lib/mix/lib/mix/compilers/elixir.ex

@@ -711,16 +711,22 @@ defmodule Mix.Compilers.Elixir do
 
   defp remove_and_purge(beam, module) do
     _ = File.rm(beam)
-    :code.purge(module)
-    :code.delete(module)
+
+    if Code.loaded?(module) do
+      :code.purge(module)
+      :code.delete(module)
+    end
   end
 
   defp purge_modules_in_path(path) do
     with {:ok, beams} <- File.ls(path) do
       Enum.each(beams, fn beam ->
         module = beam |> Path.rootname() |> String.to_atom()
-        :code.purge(module)
-        :code.delete(module)
+
+        if Code.loaded?(module) do
+          :code.purge(module)
+          :code.delete(module)
+        end
       end)
     end
   end
@@ -898,9 +904,7 @@ defmodule Mix.Compilers.Elixir do
         end
 
       for {module, _} <- data do
-        File.rm(beam_path(compile_path, module))
-        :code.purge(module)
-        :code.delete(module)
+        remove_and_purge(beam_path(compile_path, module), module)
       end
     rescue
       _ ->