Exceptions when running `frame` or `backtrace` on a Sinatra application

[arbesulo]

Problem description

When debugging an application, exceptions are raised when issuing some commands like frame or backtrace.
Evaluating expressions, viewing variables or moving up and down work normally.

The environment:

• Ruby v3.0.5
• Sinatra v3.0.6
• Byebug v11.1.3

Expected behavior

The frame/backtrace information is displayed.

Actual behavior

An exception is raised

(byebug) frame
*** undefined method `GET /' for class `Sinatra::Application'
Did you mean?  get
               gets
(byebug) 

Steps to reproduce the problem

I have created a demo repository with a minimal setup that demonstrates the problem.

#Gemfile
source 'https://rubygems.org'

gem 'sinatra'
gem 'byebug'

# app.rb

#!/bin/env ruby
require 'sinatra'
require 'byebug'

get '/' do
  debugger
  [200, {'content-type' => 'text/plain'}, 'Hello world!']
end

# Install the gems
bundle install

# Start the server
ruby app.rb -o 0.0.0.0

#Perform a request
curl localhost:4567

After hitting the debugger call frame or backtrace

# This is an old output, but the problem remains with the most up-to-date versions

== Sinatra (v2.2.0) has taken the stage on 4567 for development with backup from Puma
Puma starting in single mode...
* Puma version: 5.6.2 (ruby 2.7.5-p203) ("Birdie's Version")
*  Min threads: 0
*  Max threads: 5
*  Environment: development
*          PID: 30836
* Listening on http://0.0.0.0:4567
Use Ctrl-C to stop

[1, 9] in /Users/fer/wokspace/sinatra-byebug/app.rb
   1: #!/bin/env ruby
   2: 
   3: require 'sinatra'
   4: require 'byebug'
   5: 
   6: get '/' do
   7:   debugger
=> 8:   [200, {'content-type' => 'text/plain'}, 'Hello world!']
   9: end
(byebug) frame
*** undefined method `GET /' for class `Sinatra::Application'
Did you mean?  get
               gets
(byebug) 

Thanks in advance!