Prune tracers when fetching __ENV__ inside functions, closes #10466

Author: josevalim

lib/elixir/src/elixir_expand.erl

@@ -469,7 +469,7 @@ expand(Other, E) ->
 escape_env_entries(Meta, #{current_vars := {Read, Write}, unused_vars := {Unused, Version}} = Env0) ->
   Env1 = case Env0 of
     #{function := nil} -> Env0;
-    _ -> Env0#{lexical_tracker := nil}
+    _ -> Env0#{lexical_tracker := nil, tracers := []}
   end,
   Current = {maybe_escape_map(Read), maybe_escape_map(Write)},
   Env2 = Env1#{current_vars := Current, unused_vars := {maybe_escape_map(Unused), Version}},

lib/elixir/test/elixir/kernel/expansion_test.exs

@@ -294,6 +294,7 @@ defmodule Kernel.ExpansionTest do
     test "__ENV__" do
       env = %{__ENV__ | line: 0}
       assert expand_env(quote(do: __ENV__), env) == {Macro.escape(env), env}
+      assert %{lexical_tracker: nil, tracers: []} = __ENV__
     end
 
     test "__ENV__.accessor" do
@@ -302,6 +303,9 @@ defmodule Kernel.ExpansionTest do
 
       assert expand_env(quote(do: __ENV__.unknown), env) ==
                {quote(do: unquote(Macro.escape(env)).unknown), env}
+
+      assert __ENV__.lexical_tracker == nil
+      assert __ENV__.tracers == []
     end
   end