Bundler runtime modifications of Gemfile.lock

app_boot.rb

# Point at our Gemfile
ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)

# load rubygems & bundler
require "rubygems"
require 'bundler/setup' # Sometimes this line triggers modifications to Gemfile.lock

# Set up gems listed in the Gemfile.
Bundler.require(:default, :production)

app_boot_updated.rb

# Point at our Gemfile
ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)

# Prevent bundler from trying to update Gemfile.lock
ENV['BUNDLE_FROZEN'] = 'true'

# load rubygems & bundler
require "rubygems"
require 'bundler/setup' # With BUNDLE_FROZEN set this line won't cause problems

# Set up gems listed in the Gemfile.
Bundler.require(:default, :production)