Also load plugins from RUBYLIB

Author: djmarcin

bundler/lib/bundler/installer.rb

@@ -243,6 +243,7 @@ def load_plugins
         end
       end.flatten
       Bundler.rubygems.load_plugin_files(path_plugin_files)
+      Bundler.rubygems.load_env_plugins
     end
 
     def ensure_specs_are_compatible!

bundler/lib/bundler/rubygems_integration.rb

@@ -227,6 +227,10 @@ def load_plugin_files(files)
       Gem.load_plugin_files(files) if Gem.respond_to?(:load_plugin_files)
     end
 
+    def load_env_plugins
+      Gem.load_env_plugins if Gem.respond_to?(:load_env_plugins)
+    end
+
     def ui=(obj)
       Gem::DefaultUserInteraction.ui = obj
     end

bundler/spec/commands/install_spec.rb

@@ -432,6 +432,16 @@
         gem 'foo'
       G
     end
+
+    it "loads env plugins" do
+      plugin_msg = "hello from an env plugin!"
+      create_file "plugins/rubygems_plugin.rb", "puts '#{plugin_msg}'"
+      install_gemfile <<-G, :env => { "RUBYLIB" => bundled_app("plugins/").to_s }
+        source "#{file_uri_for(gem_repo1)}"
+        gem 'foo'
+      G
+      expect(last_command.stdboth).to include(plugin_msg)
+    end
   end
 
   describe "Ruby version in Gemfile.lock" do