fix

test/support/test_case.rb

@@ -118,6 +118,8 @@ def wait_pid pid, sec
       end
 
       false
+    rescue Errno::ECHILD
+      true
     end
 
     def kill_safely pid, name, test_info
@@ -142,10 +144,11 @@ def check_error(error, test_info)
     def kill_remote_debuggee test_info
       return unless r = test_info.remote_info
 
+      kill_safely r.pid, :remote, test_info
+      # Because the debuggee may be terminated by executing the following operations, we need to run them after `kill_safely` method.
       r.reader_thread.kill
       r.r.close
       r.w.close
-      kill_safely r.pid, :remote, test_info
     end
 
     def setup_remote_debuggee(cmd)