warn if running in a bundler env, don't load plugins

bin/vagrant

@@ -105,21 +105,8 @@ begin
   env = Vagrant::Environment.new(opts)
 
   if !Vagrant.in_installer?
-    warned = false
-
-    # If we're in a bundler environment, we assume it is for plugin
-    # development and will let the user know that.
-    if defined?(Bundler)
-      require 'bundler/shared_helpers'
-      if Bundler::SharedHelpers.in_bundle?
-        env.ui.warn(I18n.t("vagrant.general.in_bundler"))
-        env.ui.warn("")
-        warned = true
-      end
-    end
-
     # If we're not in the installer, warn.
-    env.ui.warn(I18n.t("vagrant.general.not_in_installer")) if !warned
+    env.ui.warn(I18n.t("vagrant.general.not_in_installer"))
   end
 
   begin

lib/vagrant.rb

@@ -1,17 +1,29 @@
 # This file is load before RubyGems are loaded, and allow us to actually
 # resolve plugin dependencies and load the proper versions of everything.
 
-if defined?(Vagrant)
-  raise "vagrant is somehow already loaded. bug."
-end
-
 ENV["VAGRANT_INSTALLER_EMBEDDED_DIR"] = "/Applications/Vagrant/embedded"
 
-# Initialize Bundler before we load _any_ RubyGems.
-require_relative "vagrant/bundler"
-require_relative "vagrant/plugin_manager"
-Vagrant::Bundler.instance.init!(Vagrant::PluginManager.plugins)
+if defined?(Bundler)
+  require "bundler/shared_helpers"
+  if Bundler::SharedHelpers.in_bundle?
+    puts "Vagrant appears to be running in a Bundler environment. Plugins"
+    puts "will not be loaded and plugin commands are disabled."
+    puts
+    ENV["VAGRANT_NO_PLUGINS"] = "1"
+  end
+end
 
-# Initialize Vagrant first, then load the remaining dependencies
+require_relative "vagrant/shared_helpers"
+
+if Vagrant.plugins_enabled?
+  # Initialize Bundler before we load _any_ RubyGems.
+  require_relative "vagrant/bundler"
+  require_relative "vagrant/plugin_manager"
+  Vagrant::Bundler.instance.init!(Vagrant::PluginManager.plugins)
+end
+
+# Initialize Vagrant now that our Gem paths are setup
 require "vagrant/init"
-Bundler.require(:default)
+
+# If we have plugins enabled, then load those
+Bundler.require(:default) if Vagrant.plugins_enabled?

lib/vagrant/bundler.rb

@@ -1,6 +1,6 @@
 require "tempfile"
 
-require_relative "paths"
+require_relative "shared_helpers"
 require_relative "version"
 
 module Vagrant
@@ -21,7 +21,9 @@ module Vagrant
       @configfile = Tempfile.new("vagrant-bundler-config")
       @configfile.close
 
-      # Build up the Gemfile for our Bundler context
+      # Build up the Gemfile for our Bundler context. We make sure to
+      # lock Vagrant to our current Vagrant version. In addition to that,
+      # we add all our plugin dependencies.
       @gemfile = Tempfile.new("vagrant-gemfile")
       @gemfile.puts(%Q[gem "vagrant", "= #{Vagrant::VERSION}"])
       plugins.each do |plugin|

lib/vagrant/plugin_manager.rb

@@ -1,6 +1,6 @@
 require "json"
 
-require_relative "paths"
+require_relative "shared_helpers"
 
 module Vagrant
   class PluginManager

lib/vagrant/shared_helpers.rb

@@ -1,8 +1,16 @@
 require "pathname"
 
 module Vagrant
-  # The source root is the path to the root directory of
-  # the Vagrant gem.
+  # This returns whether or not 3rd party plugins should be loaded.
+  #
+  # @return [Boolean]
+  def self.plugins_enabled?
+    !ENV["VAGRANT_NO_PLUGINS"]
+  end
+
+  # The source root is the path to the root directory of the Vagrant source.
+  #
+  # @return [Pathname]
   def self.source_root
     @source_root ||= Pathname.new(File.expand_path('../../../', __FILE__))
   end

templates/locales/en.yml

@@ -139,11 +139,6 @@ en:
 
         Old: %{old}
         New: %{new}
-      in_bundler: |-
-        You appear to be running Vagrant in a Bundler environment. Because
-        Vagrant should be run within installers (outside of Bundler), Vagrant
-        will assume that you're developing plugins and will change its behavior
-        in certain ways to better assist plugin development.
       not_in_installer: |-
         You appear to be running Vagrant outside of the official installers.
         Note that the installers are what ensure that Vagrant has all required