Weird stepping behaviour when used with `puma 6.0`

[st0012]

Your environment

• ruby -v: 3.1.2
• rdbg -v: Current master: a402e73 (but the issue can be reproduced with commits as early as c3d9257)

Describe the bug

When using the latest ruby/debug with Puma 6.0+, stepping over (or next command) could enter weird places (e.g. zeitwerk's internal). For example:

[2, 11] in ~/projects/debug-issue/app/controllers/posts_controller.rb
     2|   before_action :set_post, only: %i[ show edit update destroy ]
     3|
     4|   # GET /posts or /posts.json
     5|   def index
     6|     binding.b
=>   7|     @posts = Post.all
     8|     a = 1
     9|     b = 2
    10|   end
    11|
=>#0    PostsController#index at ~/projects/debug-issue/app/controllers/posts_controller.rb:7
  #1    ActionController::BasicImplicitRender#send_action(method="index", args=[]) at ~/.gem/ruby/3.1.2/gems/actionpack-7.0.4/lib/action_controller/metal/basic_implicit_render.rb:6
  # and 76 frames (use `bt' command for all frames)
(rdbg) n    # next command
[23, 32] in ~/.gem/ruby/3.1.2/gems/zeitwerk-2.6.6/lib/zeitwerk/kernel.rb
    23|     alias_method :zeitwerk_original_require, :require
    24|   end
    25|
    26|   # @sig (String) -> true | false
    27|   def require(path)
=>  28|     if loader = Zeitwerk::Registry.loader_for(path)
    29|       if path.end_with?(".rb")
    30|         required = zeitwerk_original_require(path)
    31|         loader.on_file_autoloaded(path) if required
    32|         required
=>#0    Kernel#require(path="/Users/hung-wulo/projects/debug-issue/ap...) at ~/.gem/ruby/3.1.2/gems/zeitwerk-2.6.6/lib/zeitwerk/kernel.rb:28
  #1    PostsController#index at ~/projects/debug-issue/app/controllers/posts_controller.rb:7
  # and 77 frames (use `bt' command for all frames)

To Reproduce

Please clone this vanilla Rails app and follow the instructions in the readme.

Expected behavior

Typing n should go to line 8 instead of entering zeitwerk's internal.

Additional context

• It's highly related to Faster next / finish by using rb_profile_frames #746. cc @WillHalto
• It works fine with puma 5.0

[ko1]

Thank you, so I'll revert #746, unfortunately.

I'll introduce another technique for Ruby 3.2, but 3.1 or before has performance issue.

[st0012]

@ko1 That sounds good, thank you 🙏

[ko1]

I confirmed that without #746 it stops at next line.

[st0012]

I can confirm that it now works as expected. Thanks for the fix 👍