5 files changed, 62 insertions, 37 deletions
diff --git a/spec/bundler/support/bundle.rb b/spec/bundler/support/bundle.rb
new file mode 100644
index 0000000000..bb21526d35
--- /dev/null
+++ b/spec/bundler/support/bundle.rb
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+require "rubygems"
+require_relative "path"
+bundler_gemspec = Spec::Path.loaded_gemspec
+bundler_gemspec.instance_variable_set(:@full_gem_path, Spec::Path.source_root)
+bundler_gemspec.activate if bundler_gemspec.respond_to?(:activate)
+load File.expand_path("bundle", Spec::Path.bindir)
diff --git a/spec/bundler/support/hax.rb b/spec/bundler/support/hax.rb
index fc8e0ad55d..8fd35890ae 100644
--- a/spec/bundler/support/hax.rb
+++ b/spec/bundler/support/hax.rb
@@ -29,7 +29,7 @@ module Gem
   end
 
   # We only need this hack for rubygems versions without the BundlerVersionFinder
-  if Gem::Version.new(Gem::VERSION) < Gem::Version.new("2.7.0")
+  if Gem.rubygems_version < Gem::Version.new("2.7.0")
     @path_to_default_spec_map.delete_if do |_path, spec|
       spec.name == "bundler"
     end
diff --git a/spec/bundler/support/helpers.rb b/spec/bundler/support/helpers.rb
index 7e2e92a1ec..73dd508e54 100644
--- a/spec/bundler/support/helpers.rb
+++ b/spec/bundler/support/helpers.rb
@@ -10,7 +10,7 @@ module Spec
 
     def reset!
       Dir.glob("#{tmp}/{gems/*,*}", File::FNM_DOTMATCH).each do |dir|
-        next if %w[base base_system remote1 gems rubygems . ..].include?(File.basename(dir))
+        next if %w[base base_system remote1 rubocop gems rubygems . ..].include?(File.basename(dir))
         FileUtils.rm_rf(dir)
       end
       FileUtils.mkdir_p(home)
diff --git a/spec/bundler/support/path.rb b/spec/bundler/support/path.rb
index 56d3c71f3c..483c7da347 100644
--- a/spec/bundler/support/path.rb
+++ b/spec/bundler/support/path.rb
@@ -6,7 +6,7 @@ require "rbconfig"
 module Spec
   module Path
     def source_root
-      @source_root ||= Pathname.new(ruby_core? ? "../../../.." : "../../..").expand_path(__FILE__)
+      @source_root ||= Pathname.new(ruby_core? ? "../../.." : "../..").expand_path(__dir__)
     end
 
     def root
@@ -30,7 +30,11 @@ module Spec
     end
 
     def test_gemfile
-      @test_gemfile ||= source_root.join(ruby_core? ? "tool/bundler/test_gems.rb" : "test_gems.rb")
+      @test_gemfile ||= source_root.join("tool/bundler/test_gems.rb")
+    end
+
+    def rubocop_gemfile
+      @rubocop_gemfile ||= source_root.join(rubocop_gemfile_basename)
     end
 
     def dev_gemfile
@@ -119,7 +123,7 @@ module Spec
     end
 
     def vendored_gems(path = nil)
-      bundled_app(*["vendor/bundle", Gem.ruby_engine, RbConfig::CONFIG["ruby_version"], path].compact)
+      scoped_gem_path(bundled_app("vendor/bundle")).join(*[path].compact)
     end
 
     def cached_gem(path)
@@ -138,6 +142,10 @@ module Spec
       tmp.join("gems/base")
     end
 
+    def rubocop_gems
+      tmp.join("gems/rubocop")
+    end
+
     def file_uri_for(path)
       protocol = "file://"
       root = Gem.win_platform? ? "/" : ""
@@ -178,7 +186,11 @@ module Spec
     end
 
     def local_gem_path(*path, base: bundled_app)
-      base.join(*[".bundle", Gem.ruby_engine, RbConfig::CONFIG["ruby_version"], *path].compact)
+      scoped_gem_path(base.join(".bundle")).join(*path)
+    end
+
+    def scoped_gem_path(base)
+      base.join(Gem.ruby_engine, RbConfig::CONFIG["ruby_version"])
     end
 
     def lib_path(*args)
@@ -251,6 +263,10 @@ module Spec
       !git_root.join(".git").directory?
     end
 
+    def rubocop_gemfile_basename
+      source_root.join("tool/bundler/#{RUBY_VERSION.start_with?("2.3") ? "rubocop23_gems.rb" : "rubocop_gems.rb"}")
+    end
+
     extend self
   end
 end
diff --git a/spec/bundler/support/rubygems_ext.rb b/spec/bundler/support/rubygems_ext.rb
index d743a76391..c6202ebb1f 100644
--- a/spec/bundler/support/rubygems_ext.rb
+++ b/spec/bundler/support/rubygems_ext.rb
@@ -9,7 +9,7 @@ module Spec
     extend self
 
     def dev_setup
-      install_gems(dev_gemfile, dev_lockfile)
+      install_gems(dev_gemfile)
     end
 
     def gem_load(gem_name, bin_container)
@@ -39,18 +39,19 @@ module Spec
     end
 
     def install_parallel_test_deps
+      Gem.clear_paths
+
       require "parallel"
+      require "fileutils"
 
-      prev_env_test_number = ENV["TEST_ENV_NUMBER"]
+      install_test_deps
 
-      begin
-        Parallel.processor_count.times do |n|
-          ENV["TEST_ENV_NUMBER"] = (n + 1).to_s
+      (2..Parallel.processor_count).each do |n|
+        source = Path.source_root.join("tmp", "1")
+        destination = Path.source_root.join("tmp", n.to_s)
 
-          install_test_deps
-        end
-      ensure
-        ENV["TEST_ENV_NUMBER"] = prev_env_test_number
+        FileUtils.rm_rf destination
+        FileUtils.cp_r source, destination
       end
     end
 
@@ -66,25 +67,12 @@ module Spec
     def install_test_deps
       setup_test_paths
 
-      workaround_loaded_specs_issue
-
-      install_gems(test_gemfile, test_lockfile)
+      install_gems(test_gemfile)
+      install_gems(rubocop_gemfile, Path.rubocop_gems.to_s)
     end
 
     private
 
-    # Some rubygems versions include loaded specs when loading gemspec stubs
-    # from the file system. In this situation, that makes bundler incorrectly
-    # assume that `rake` is already installed at `tmp/` because it's installed
-    # globally, and makes it skip installing it to the proper location for our
-    # tests. To workaround, we remove `rake` from the loaded specs when running
-    # under those versions, so that `bundler` does the right thing.
-    def workaround_loaded_specs_issue
-      current_rubygems_version = Gem::Version.new(Gem::VERSION)
-
-      Gem.loaded_specs.delete("rake") if current_rubygems_version >= Gem::Version.new("3.0.0.beta2") && current_rubygems_version < Gem::Version.new("3.2.0")
-    end
-
     def gem_load_and_activate(gem_name, bin_container)
       gem_activate(gem_name)
       load Gem.bin_path(gem_name, bin_container)
@@ -98,14 +86,27 @@ module Spec
       gem gem_name, gem_requirement
     end
 
-    def install_gems(gemfile, lockfile)
+    def install_gems(gemfile, path = nil)
       old_gemfile = ENV["BUNDLE_GEMFILE"]
       ENV["BUNDLE_GEMFILE"] = gemfile.to_s
-      require "bundler"
-      definition = Bundler::Definition.build(gemfile, lockfile, nil)
-      definition.validate_runtime!
-      Bundler::Installer.install(Path.source_root, definition, :path => ENV["GEM_HOME"])
+
+      if path
+        old_path = ENV["BUNDLE_PATH"]
+        ENV["BUNDLE_PATH"] = path
+      else
+        old_path__system = ENV["BUNDLE_PATH__SYSTEM"]
+        ENV["BUNDLE_PATH__SYSTEM"] = "true"
+      end
+
+      output = `#{Gem.ruby} #{File.expand_path("support/bundle.rb", Path.spec_dir)} install`
+      raise "Error when installing gems in #{gemfile}: #{output}" unless $?.success?
     ensure
+      if path
+        ENV["BUNDLE_PATH"] = old_path
+      else
+        ENV["BUNDLE_PATH__SYSTEM"] = old_path__system
+      end
+
       ENV["BUNDLE_GEMFILE"] = old_gemfile
     end
 
@@ -113,8 +114,8 @@ module Spec
       Path.test_gemfile
     end
 
-    def test_lockfile
-      lockfile_for(test_gemfile)
+    def rubocop_gemfile
+      Path.rubocop_gemfile
     end
 
     def dev_gemfile