The test framework for DAP sometimes raises "ArgumentError"

[ono-max]

Your environment

• ruby -v:
  ruby 2.6.7p197 (2021-04-05 revision 67941) [x86_64-darwin20]

Describe the bug
The test framework for DAP sometimes raises "ArgumentError" as follows:

$ rake test_dap
/Users/naotto/workspace/debug/lib/debug/client.rb:178: warning: assigned but unused variable - e
Tests on local and remote. You can disable remote tests with RUBY_DEBUG_TEST_NO_REMOTE=1.
Loaded suite /Users/naotto/.rbenv/versions/2.6.7/lib/ruby/gems/2.6.0/gems/rake-13.0.6/lib/rake/rake_test_loader
Started
....#<Thread:0x00007fae08856f48@/Users/naotto/workspace/debug/test/support/dap_utils.rb:152 run> terminated with exception (report_on_exception is true):
/Users/naotto/workspace/debug/test/support/dap_utils.rb:8:in `recv_request': wrong number of arguments (given 1, expected 2) (ArgumentError)
	from /Users/naotto/workspace/debug/test/support/dap_utils.rb:20:in `recv_request'
	from /Users/naotto/workspace/debug/test/support/dap_utils.rb:153:in `block in connect_to_dap_server'
F
================================================================================
Failure: test_hover_works_correctly(DEBUGGER__::HoverTest1638791703):
  -------------------------
  | All Protocol Messages |
  -------------------------

  V>D {"seq":1,"command":"initialize","arguments":{"clientID":"vscode","clientName":"Visual Studio Code","adapterID":"rdbg","pathFormat":"path","linesStartAt1":true,"columnsStartAt1":true,"supportsVariableType":true,"supportsVariablePaging":true,"supportsRunInTerminalRequest":true,"locale":"en-us","supportsProgressReporting":true,"supportsInvalidatedEvent":true,"supportsMemoryReferences":true},"type":"request"}
  V>D {"seq":2,"command":"attach","arguments":{"type":"rdbg","name":"Attach with rdbg","request":"attach","rdbgPath":"/Users/naotto/workspace/debug/exe/rdbg","debugPort":"/var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/ruby-debug-sock-501/ruby-debug-naotto-8845","autoAttach":true,"__sessionId":"141d9c79-3669-43ec-ac1f-e62598c5a65a"},"type":"request"}
  V>D {"seq":3,"command":"setFunctionBreakpoints","arguments":{"breakpoints":[]},"type":"request"}
  V>D {"seq":4,"command":"setExceptionBreakpoints","arguments":{"filters":[],"filterOptions":[{"filterId":"RuntimeError"}]},"type":"request"}
  V>D {"seq":5,"command":"configurationDone","type":"request"}

  --------------------------
  | Last Protocol Messages |
  --------------------------

  {
    "seq": 2,
    "command": "attach",
    "arguments": {
      "type": "rdbg",
      "name": "Attach with rdbg",
      "request": "attach",
      "rdbgPath": "/Users/naotto/workspace/debug/exe/rdbg",
      "debugPort": "/var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/ruby-debug-sock-501/ruby-debug-naotto-8845",
      "autoAttach": true,
      "__sessionId": "141d9c79-3669-43ec-ac1f-e62598c5a65a"
    },
    "type": "request"
  }
  {
    "seq": 3,
    "command": "setFunctionBreakpoints",
    "arguments": {
      "breakpoints": [

      ]
    },
    "type": "request"
  }
  {
    "seq": 4,
    "command": "setExceptionBreakpoints",
    "arguments": {
      "filters": [

      ],
      "filterOptions": [
        {
          "filterId": "RuntimeError"
        }
      ]
    },
    "type": "request"
  }
  {
    "seq": 5,
    "command": "configurationDone",
    "type": "request"
  }

  --------------------
  | Debuggee Session |
  --------------------

  > EBUGGER: Debugger can attach via UNIX domain socket (/var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/ruby-debug-sock-501/ruby-debug-naotto-18337-5)
  > DEBUGGER: Connected.


  -------------------
  | Failure Message |
  -------------------

  TIMEOUT ERROR (10 sec) while waiting for the following response.
  {
    "seq": 7,
    "type": "event",
    "event": "stopped",
    "body": {
      "reason": "pause",
      "threadId": 1,
      "allThreadsStopped": true
    }
  }.
/Users/naotto/workspace/debug/test/support/assertions.rb:79:in `assert_block'
/Users/naotto/workspace/debug/test/support/dap_utils.rb:255:in `rescue in run_dap_scenario'
/Users/naotto/workspace/debug/test/support/dap_utils.rb:254:in `run_dap_scenario'
/Users/naotto/workspace/debug/test/dap/hover_test.rb:17:in `test_hover_works_correctly'
     14:     RUBY
     15:
     16:     def test_hover_works_correctly
  => 17:       run_dap_scenario PROGRAM do
     18:         [
     19:           *INITIALIZE_MSG,
     20:           {
================================================================================
...
Finished in 19.179482 seconds.
--------------------------------------------------------------------------------
8 tests, 1862 assertions, 1 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications
87.5% passed
--------------------------------------------------------------------------------
0.42 tests/s, 97.08 assertions/s
rake aborted!
Command failed with status (1)

Tasks: TOP => test_dap

Expected behavior
It should not raise "ArgumentError".

Additional context
Add any other context about the problem here.