Remove unnecessary rubygems monkeypatch

Instead, make sure we always load the local copy of bundler during
specs, and never end up using the default copy.

lib/bundler.rb

@@ -299,7 +299,7 @@ def unbundled_env
       env.delete_if {|k, _| k[0, 7] == "BUNDLE_" }
 
       if env.key?("RUBYOPT")
-        env["RUBYOPT"] = env["RUBYOPT"].sub "-rbundler/setup", ""
+        env["RUBYOPT"] = env["RUBYOPT"].sub "-r#{File.expand_path("bundler/setup", __dir__)}", ""
       end
 
       if env.key?("RUBYLIB")

spec/commands/pristine_spec.rb

@@ -42,8 +42,7 @@
       expect(changes_txt).to_not be_file
     end
 
-    it "does not delete the bundler gem", :rubygems => ">= 2.6.2" do
-      ENV["BUNDLER_SPEC_KEEP_DEFAULT_BUNDLER_GEM"] = "true"
+    it "does not delete the bundler gem" do
       system_gems :bundler
       bundle! "install"
       bundle! "pristine", :system_bundler => true

spec/install/gemfile/groups_spec.rb

@@ -333,7 +333,7 @@
       G
 
       ruby <<-R
-        require "bundler"
+        require "#{__dir__}/../../../lib/bundler"
         Bundler.setup :default
         Bundler.require :default
         puts RACK

spec/install/gems/compact_index_spec.rb

@@ -528,6 +528,8 @@ def require(*args)
       gem "rack"
     G
 
+    system_gems :bundler
+
     bundle "install --binstubs", :artifice => "compact_index"
 
     gembin "rackup"

spec/install/gems/dependency_api_spec.rb

@@ -502,6 +502,8 @@ def require(*args)
       gem "rack"
     G
 
+    system_gems :bundler
+
     bundle "install --binstubs", :artifice => "endpoint"
 
     gembin "rackup"

spec/plugins/source/example_spec.rb

@@ -6,7 +6,6 @@
       build_repo2 do
         build_plugin "bundler-source-mpath" do |s|
           s.write "plugins.rb", <<-RUBY
-            require "bundler/vendored_fileutils"
             require "bundler-source-mpath"
 
             class MPath < Bundler::Plugin::API

spec/realworld/double_check_spec.rb

@@ -25,9 +25,9 @@
     RUBY
 
     cmd = <<-RUBY
-      require "bundler"
+      require #{File.expand_path("../../../lib/bundler.rb", __FILE__).dump}
       require #{File.expand_path("../../support/artifice/vcr.rb", __FILE__).dump}
-      require "bundler/inline"
+      require #{File.expand_path("../../../lib/bundler/inline.rb", __FILE__).dump}
       gemfile(true) do
         source "https://rubygems.org"
         gem "rails", path: "."

spec/runtime/executable_spec.rb

@@ -9,7 +9,7 @@
   end
 
   it "runs the bundled command when in the bundle" do
-    bundle! "binstubs rack"
+    bundle! "binstubs rack bundler"
 
     build_gem "rack", "2.0", :to_system => true do |s|
       s.executables = "rackup"
@@ -20,7 +20,7 @@
   end
 
   it "allows the location of the gem stubs to be specified" do
-    bundle! "binstubs rack", :path => "gbin"
+    bundle! "binstubs rack bundler", :path => "gbin"
 
     expect(bundled_app("bin")).not_to exist
     expect(bundled_app("gbin/rackup")).to exist
@@ -30,19 +30,19 @@
   end
 
   it "allows absolute paths as a specification of where to install bin stubs" do
-    bundle! "binstubs rack", :path => tmp("bin")
+    bundle! "binstubs rack bundler", :path => tmp("bin")
 
     gembin tmp("bin/rackup")
     expect(out).to eq("1.0.0")
   end
 
   it "uses the default ruby install name when shebang is not specified" do
-    bundle! "binstubs rack"
+    bundle! "binstubs rack bundler"
     expect(File.open("bin/rackup").gets).to eq("#!/usr/bin/env #{RbConfig::CONFIG["ruby_install_name"]}\n")
   end
 
   it "allows the name of the shebang executable to be specified" do
-    bundle! "binstubs rack", :shebang => "ruby-foo"
+    bundle! "binstubs rack bundler", :shebang => "ruby-foo"
     expect(File.open("bin/rackup").gets).to eq("#!/usr/bin/env ruby-foo\n")
   end
 
@@ -69,7 +69,7 @@
       gem "rack", :path => "#{lib_path("rack")}"
     G
 
-    bundle! "binstubs rack"
+    bundle! "binstubs rack bundler"
 
     build_gem "rack", "2.0", :to_system => true do |s|
       s.executables = "rackup"
@@ -138,7 +138,7 @@
 
     create_file("bin/rackup", "OMG")
 
-    bundle! "binstubs rack"
+    bundle! "binstubs rack bundler"
 
     expect(bundled_app("bin/rackup").read).to_not eq("OMG")
   end
@@ -162,12 +162,12 @@
     bundle "install"
     bundle! "binstubs bindir"
 
-    # remove user settings
-    ENV["BUNDLE_GEMFILE"] = nil
-
     # run binstub for non default Gemfile
     gembin "foo"
 
+    # remove user settings
+    ENV["BUNDLE_GEMFILE"] = nil
+
     expect(exitstatus).to eq(0) if exitstatus
     expect(out).to eq("1.0")
   end

spec/runtime/inline_spec.rb

@@ -2,7 +2,7 @@
 
 RSpec.describe "bundler/inline#gemfile" do
   def script(code, options = {})
-    requires = ["bundler/inline"]
+    requires = ["../../lib/bundler/inline.rb"]
     requires.unshift File.expand_path("../../support/artifice/" + options.delete(:artifice) + ".rb", __FILE__) if options.key?(:artifice)
     requires = requires.map {|r| "require '#{r}'" }.join("\n")
     @out = ruby("#{requires}\n\n" + code, options)
@@ -96,7 +96,7 @@ def script(code, options = {})
 
   it "lets me use my own ui object" do
     script <<-RUBY, :artifice => "endpoint"
-      require 'bundler'
+      require '../../lib/bundler'
       class MyBundlerUI < Bundler::UI::Silent
         def confirm(msg, newline = nil)
           puts "CONFIRMED!"
@@ -140,7 +140,7 @@ def confirm(msg, newline = nil)
 
   it "does not mutate the option argument" do
     script <<-RUBY
-      require 'bundler'
+      require '../../lib/bundler'
       options = { :ui => Bundler::UI::Shell.new }
       gemfile(false, options) do
         path "#{lib_path}" do

spec/runtime/load_spec.rb

@@ -80,7 +80,7 @@
       G
 
       ruby! <<-RUBY
-        require "bundler"
+        require "../../lib/bundler"
         Bundler.setup :default
         Bundler.require :default
         puts RACK

spec/runtime/require_spec.rb

@@ -193,7 +193,7 @@
       G
 
       cmd = <<-RUBY
-        require 'bundler'
+        require '../../lib/bundler'
         Bundler.require
       RUBY
       ruby(cmd)