Script to demonstrate [an alleged bug in bundler, in that requiring bundler/setup can modify the Gemfile.lock. See: https://github.com/bundler/bundler/issues/2710

bundler_environment

Note: This is the output of "bundle env" _after_ the test script has run.  The Gemfile and Gemfile.lock therefore show the modified state of those two file, not their original state.

Bundler 1.3.5
Ruby 1.9.3 (2013-06-27 patchlevel 448) [i686-linux]
Rubygems 2.0.7
rvm 1.22.9 (stable)
GEM_HOME /home/wayne/.rvm/gems/ruby-1.9.3-p448
GEM_PATH /home/wayne/.rvm/gems/ruby-1.9.3-p448:/home/wayne/.rvm/gems/ruby-1.9.3-p448@global

Bundler settings
  bin_path
    Set via BUNDLE_BIN_PATH: "/home/wayne/.rvm/gems/ruby-1.9.3-p448/gems/bundler-1.3.5/bin/bundle"
  gemfile
    Set via BUNDLE_GEMFILE: "/tmp/d20131112-16493-d4xcy2/Gemfile"


Gemfile
source "http://rubygems.org"


Gemfile.lock
GEM
  remote: http://rubygems.org/
  specs:

PLATFORMS
  ruby

DEPENDENCIES

test.rb

require 'fileutils'
require 'tmpdir'

Dir.mktmpdir do |temp_dir|
  Dir.chdir(temp_dir) do
    File.open('Gemfile', 'w') do |file|
      file.puts 'source "http://rubygems.org"'
      file.puts 'gem "zip"'
    end
    system 'bundle install'
    FileUtils.cp 'Gemfile.lock', 'Gemfile.lock.orig'
    File.open('Gemfile', 'w') do |file|
      file.puts 'source "http://rubygems.org"'
    end
    require 'bundler/setup'
    system 'diff -u Gemfile.lock.orig Gemfile.lock'
  end
end

test_output

Fetching gem metadata from http://rubygems.org/..
Resolving dependencies...
Using zip (2.0.2)
Using bundler (1.3.5)
Your bundle is complete!
Use `bundle show [gemname]` to see where a bundled gem is installed.
--- Gemfile.lock.orig   2013-11-12 10:42:21.000000000 -0700
+++ Gemfile.lock        2013-11-12 10:42:21.000000000 -0700
@@ -1,10 +1,8 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    zip (2.0.2)

 PLATFORMS
   ruby

 DEPENDENCIES
-  zip