refactored plugin code: 1. should not warn when activate called twice on a gem that has already been activated (but ceases to be accessible due to bundler, robgleeson's bug). 2. calling activate on a non-existent plugin should warn not raise

lib/pry/command_processor.rb

@@ -126,7 +126,6 @@ class Pry
 
       ret = commands.run_command(context, command, *args)
 
-      # Tick, tock, im getting rid of this shit soon.
       options[:val].replace("")
 
       ret

lib/pry/plugins.rb

@@ -1,9 +1,17 @@
 class Pry
   class PluginManager
     PRY_PLUGIN_PREFIX = /^pry-/
-    PluginNotFound = Class.new(LoadError)
 
-    MessageSink = Object.new.tap { |o| def o.method_missing(*args) end }
+    # Placeholder when no associated gem found, displays warning
+    class NoPlugin
+      def initialize(name)
+        @name = name
+      end
+
+      def method_missing(*args)
+        $stderr.puts "Warning: The plugin '#{@name}' was not found! (no gem found)"
+      end
+    end
 
     class Plugin
       attr_accessor :name, :gem_name, :enabled, :spec, :active
@@ -12,22 +20,25 @@ class Pry
         @name, @gem_name, @enabled, @spec = name, gem_name, enabled, spec
       end
 
-      # Disable a plugin.
+      # Disable a plugin. (prevents plugin from being loaded, cannot
+      # disable an already activated plugin)
       def disable!
         self.enabled = false
       end
 
-      # Enable a plugin.
+      # Enable a plugin. (does not load it immediately but puts on
+      # 'white list' to be loaded)
       def enable!
         self.enabled = true
       end
 
-      # Activate the plugin (require the gem).
+      # Activate the plugin (require the gem - enables/loads the
+      # plugin immediately at point of call, even if plugin is disabled)
       def activate!
         begin
-          require gem_name
+          require gem_name if !active?
         rescue LoadError
-          $stderr.puts "Warning: The plugin '#{gem_name}' was not found!"
+          $stderr.puts "Warning: The plugin '#{gem_name}' was not found! (gem found but could not be loaded)"
         end
         self.active = true
         self.enabled = true
@@ -55,7 +66,7 @@ class Pry
     # @return [Hash] A hash with all plugin names (minus the 'pry-') as
     #   keys and Plugin objects as values.
     def plugins
-      h = Pry.config.plugins.strict_loading ? {} : Hash.new { MessageSink }
+      h = Hash.new { |_, key| NoPlugin.new(key) }
       @plugins.each do |plugin|
         h[plugin.name] = plugin
       end