add sleep for timing issue

Author: ko1

test/protocol/eval_test.rb

@@ -41,15 +41,17 @@ def test_eval_executes_commands
 
   class EvaluateOnSomeFramesTest < ProtocolTestCase
     PROGRAM = <<~RUBY
-      1| a = 2
+      1| a = 2; sleep 0.1
       2| def foo
       3|   a = 4
       4| end
       5| foo
+      6| nil
     RUBY
 
     def test_eval_evaluates_arithmetic_expressions
       run_protocol_scenario PROGRAM do
+        sleep 0.1
         req_add_breakpoint 4
         req_continue
         assert_repl_result({value: '4', type: 'Integer'}, 'a', frame_idx: 0)