There is the error when I use Chrome debugging.

[ono-max]

Your environment

• ruby -v: ruby 3.0.2p107 (2021-07-07 revision 0db68f0233) [x86_64-darwin19]

Describe the bug

1. Set breakpoints on the third line.
2. Resume Script Execution.
3. Step Into twice.

% exe/rdbg --port 12345 target.rb
[1, 4] in target.rb
=>   1| a=1
     2| b=1
     3| c=1
     4| d=1
=>#0	<main> at target.rb:1
(rdbg) open chrome    # command
DEBUGGER: wait for debugger connection...
DEBUGGER: Debugger can attach via TCP/IP (127.0.0.1:12345)
DEBUGGER: With Chrome browser, type the following URL in the address-bar:

   devtools://devtools/bundled/inspector.html?ws=127.0.0.1:12345

DEBUGGER: Connected.
["DEBUGGER Exception: /Users/s15236/workspace/debug/lib/debug/thread_client.rb:966",
 #<NoMethodError: undefined method `match' for nil:NilClass>,
 ["/Users/s15236/workspace/debug/lib/debug/server_cdp.rb:297:in `block in process_cdp'",
  "/Users/s15236/workspace/debug/lib/debug/server_cdp.rb:294:in `map'",
  "/Users/s15236/workspace/debug/lib/debug/server_cdp.rb:294:in `with_index'",
  "/Users/s15236/workspace/debug/lib/debug/server_cdp.rb:294:in `process_cdp'",
  "/Users/s15236/workspace/debug/lib/debug/thread_client.rb:957:in `wait_next_action_'",
  "/Users/s15236/workspace/debug/lib/debug/thread_client.rb:657:in `wait_next_action'",
  "/Users/s15236/workspace/debug/lib/debug/thread_client.rb:277:in `suspend'",
  "/Users/s15236/workspace/debug/lib/debug/thread_client.rb:311:in `block in step_tp'",
  "<internal:kernel>:20:in `class'",
  "/Users/s15236/workspace/debug/lib/debug/config.rb:171:in `config'",
  "/Users/s15236/workspace/debug/lib/debug/config.rb:68:in `[]'",
  "/Users/s15236/workspace/debug/lib/debug/console.rb:138:in `history_file'",
  "/Users/s15236/workspace/debug/lib/debug/console.rb:157:in `block in initialize'"]]
/Users/s15236/workspace/debug/lib/debug/server_cdp.rb:297:in `block in process_cdp': undefined method `match' for nil:NilClass (NoMethodError)
	from /Users/s15236/workspace/debug/lib/debug/server_cdp.rb:294:in `map'
	from /Users/s15236/workspace/debug/lib/debug/server_cdp.rb:294:in `with_index'
	from /Users/s15236/workspace/debug/lib/debug/server_cdp.rb:294:in `process_cdp'
	from /Users/s15236/workspace/debug/lib/debug/thread_client.rb:957:in `wait_next_action_'
	from /Users/s15236/workspace/debug/lib/debug/thread_client.rb:657:in `wait_next_action'
	from /Users/s15236/workspace/debug/lib/debug/thread_client.rb:277:in `suspend'
	from /Users/s15236/workspace/debug/lib/debug/thread_client.rb:311:in `block in step_tp'
	from <internal:kernel>:20:in `class'
	from /Users/s15236/workspace/debug/lib/debug/config.rb:171:in `config'
	from /Users/s15236/workspace/debug/lib/debug/config.rb:68:in `[]'
	from /Users/s15236/workspace/debug/lib/debug/console.rb:138:in `history_file'
	from /Users/s15236/workspace/debug/lib/debug/console.rb:157:in `block in initialize'
DEBUGGER: Disconnected.

To Reproduce

a=1
b=1
c=1
d=1

Expected behavior
It should be finished without any errors.