After 5 months I believe it is safe to get rid of this code

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## [0.6.0](https://github.com/fgrehm/vagrant-cachier/compare/v0.5.1...master) (unreleased)
 
+BACKWARDS INCOMPATIBILITY:
+
+  - Automatic handling of multiple machine scoped cache dirs from versions
+    prior to 0.3.0 of this plugin was removed.
 
 ## [0.5.1](https://github.com/fgrehm/vagrant-cachier/compare/v0.5.0...v0.5.1) (Dec 20, 2013)
 

lib/vagrant-cachier/action/ensure_single_cache_root.rb

@@ -1,64 +0,0 @@
-require_relative '../errors'
-
-module VagrantPlugins
-  module Cachier
-    class Action
-      class EnsureSingleCacheRoot
-        def initialize(app, env)
-          @app = app
-        end
-
-        def call(env)
-          @env = env
-
-          # If the cache is scoped to boxes or the existing cache dirs are not
-          # provider specific, there's nothing we need to do
-          if cache_scoped_to_machine? && provider_specific_cache_dirs.any?
-            ensure_single_cache_root_exists!
-          end
-
-          @app.call(env)
-        end
-
-        def cache_scoped_to_machine?
-          @env[:machine].config.cache.enabled? &&
-            @env[:machine].config.cache.scope.to_sym == :machine
-        end
-
-        def ensure_single_cache_root_exists!
-          if provider_specific_cache_dirs.size > 1
-            cache_dirs = provider_specific_cache_dirs.map do |dir|
-              "  - #{dir.to_s.gsub(/^#{@env[:root_path]}\//, '')}"
-            end
-            machine_path = @env[:machine].data_dir.parent.to_s.gsub(/^#{@env[:root_path]}\//, '')
-            raise Cachier::Errors::MultipleProviderSpecificCacheDirsFound,
-                      machine:      @env[:machine].name,
-                      machine_path: machine_path,
-                      dirs:         cache_dirs.join("\n")
-          else
-            current_path = provider_specific_cache_dirs.first.to_s.gsub(/^#{@env[:root_path]}\//, '')
-            new_path     = @env[:machine].data_dir.parent.join('cache')
-            FileUtils.rm_rf new_path.to_s if new_path.directory?
-
-            new_path = new_path.to_s.gsub(/^#{@env[:root_path]}\//, '')
-            # If we got here there is a single provider specific cacher dir, so
-            # let's be nice with users and just fix it ;)
-            @env[:ui].warn I18n.t('vagrant_cachier.will_fix_machine_cache_dir',
-                                  current_path: current_path,
-                                  new_path:     new_path)
-            FileUtils.mv current_path, new_path
-          end
-        end
-
-        def provider_specific_cache_dirs
-          return @provider_specific_cache_dirs if @provider_specific_cache_dirs
-
-          # By default data_dir points to ./.vagrant/machines/<NAME>/<PROVIDER>,
-          # so we go one directory up
-          machine_dir = @env[:machine].data_dir.parent
-          @provider_specific_cache_dirs = Pathname.glob(machine_dir.join('*/cache'))
-        end
-      end
-    end
-  end
-end

lib/vagrant-cachier/plugin.rb

@@ -70,21 +70,6 @@ module VagrantPlugins
         Cap::SuSE::ZypperCacheDir
       end
 
-      # TODO: This should be generic, we don't want to hard code every single
-      #       possible provider action class that Vagrant might have
-      ensure_single_cache_root = lambda do |hook|
-        require_relative 'action/ensure_single_cache_root'
-        hook.before VagrantPlugins::ProviderVirtualBox::Action::Boot, Action::EnsureSingleCacheRoot
-
-        if defined?(Vagrant::LXC)
-          # TODO: Require just the boot action file once its "require dependencies" are sorted out
-          require 'vagrant-lxc/action'
-          hook.before Vagrant::LXC::Action::Boot, Action::EnsureSingleCacheRoot
-        end
-      end
-      action_hook 'ensure-single-cache-root-exists-on-up',     :machine_action_up,     &ensure_single_cache_root
-      action_hook 'ensure-single-cache-root-exists-on-reload', :machine_action_reload, &ensure_single_cache_root
-
       clean_action_hook = lambda do |hook|
         require_relative 'action/clean'
         hook.before Vagrant::Action::Builtin::GracefulHalt, Action::Clean