There is this trick.
What you need to do is
# Copy the definition of the debundle! method into your ~/.irbrc
# Call 'debundle!' from IRB when you need to.
(as explained at the top of the file)
The text as it appears on the referred to site:
debundle.rb allows you to require gems that are not in your Gemfile when inspecting
programs that are run with Bundler.
Use at your own risk!
Paste the code of debundle.rb and you are done! A good place would be your .irbrc file
before requiring irbtools.
The code is directly taken from pry-debundle.
Please look there for any further information. This repo exists to simplify debundling
without using the pry repl.