diff --git a/History.markdown b/History.markdown
index 95bdc53a94..b3a2929ecb 100644
--- a/History.markdown
+++ b/History.markdown
@@ -1,5 +1,15 @@
 ## rspec-core release history (incomplete)
 
+### 2.2.1 / in development
+
+[full changelog](http://github.com/rspec/rspec-core/compare/v2.2.0...master)
+
+* Bug fixes
+  * alias_method instead of override Kernel#method_missing (John Wilger)
+  * changed --autotest to --tty in generated command (MIKAMI Yoshiyuki) 
+  * revert change to debugger (had introduced conflict with Rails)
+    * also restored --debugger/-debug option
+
 ### 2.2.0 / 2010-11-28
 
 [full changelog](http://github.com/rspec/rspec-core/compare/v2.1.0...v2.2.0)
diff --git a/Upgrade.markdown b/Upgrade.markdown
index 4fb4ce942b..4fde130d58 100644
--- a/Upgrade.markdown
+++ b/Upgrade.markdown
@@ -1,4 +1,4 @@
-# rspec-core-2.2 (in development)
+# rspec-core-2.2
 
 ## FASTER!
 
@@ -94,7 +94,7 @@ JRuby installation to a newer release that allows the example to pass, RSpec
 will report it as a failure (`Expected pending '...' to fail.  No Error was raised.`),
 so that know that you can remove the call to `pending`.
 
-# rspec-core-2.0
+# New features in rspec-core-2.0
 
 ### Runner
 
diff --git a/lib/autotest/rspec2.rb b/lib/autotest/rspec2.rb
index 8c8728d1b5..c61772ac63 100644
--- a/lib/autotest/rspec2.rb
+++ b/lib/autotest/rspec2.rb
@@ -41,7 +41,7 @@ def consolidate_failures(failed)
 
   def make_test_cmd(files_to_test)
     files_to_test.empty? ? '' :
-      "#{bundle_exec}#{ruby} #{require_rubygems}-S #{SPEC_PROGRAM} --autotest #{normalize(files_to_test).keys.flatten.map { |f| "'#{f}'"}.join(' ')}"
+      "#{bundle_exec}#{ruby} #{require_rubygems}-S #{SPEC_PROGRAM} --tty #{normalize(files_to_test).keys.flatten.map { |f| "'#{f}'"}.join(' ')}"
   end
 
   def bundle_exec
diff --git a/lib/rspec/core/configuration.rb b/lib/rspec/core/configuration.rb
index fbc22073ea..180be43048 100644
--- a/lib/rspec/core/configuration.rb
+++ b/lib/rspec/core/configuration.rb
@@ -176,11 +176,21 @@ def requires=(paths)
       end
 
       def debug=(bool)
-        RSpec.warn_deprecation <<-WARNING
-The debug option (config.debug = true or --debug/-d on the command line)
-is deprecated and no longer has any effect. This message will be removed
-from future versions of RSpec.
-WARNING
+        return unless bool
+        begin
+          require 'ruby-debug'
+        rescue LoadError
+          raise <<-EOM
+
+#{'*'*50}
+You must install ruby-debug to run rspec with the --debug option.
+
+If you have ruby-debug installed as a ruby gem, then you need to either
+require 'rubygems' or configure the RUBYOPT environment variable with
+the value 'rubygems'.
+#{'*'*50}
+EOM
+        end
       end
 
       def line_number=(line_number)
diff --git a/lib/rspec/core/extensions/kernel.rb b/lib/rspec/core/extensions/kernel.rb
index c7587ce54e..ae40361495 100644
--- a/lib/rspec/core/extensions/kernel.rb
+++ b/lib/rspec/core/extensions/kernel.rb
@@ -1,25 +1,5 @@
 module Kernel
-
-  private
-
-  def method_missing(m, *a)
-    if m.to_s == 'debugger'
-      begin
-        require 'ruby-debug'
-        debugger
-      rescue LoadError => e
-        warn <<-EOM
-#{'*'*50}
-The debugger statement on the following line was ignored:
-
-  #{caller(0).detect {|l| l !~ /method_missing/}}
- 
-To use the debugger statement, you must install ruby-debug.
-#{'*'*50}
-EOM
-      end
-    else
-      super
-    end
-  end
+  def debugger(*args)
+    RSpec.configuration.error_stream.puts "debugger statement ignored, use -d or --debug option to enable debugging\n#{caller(0)[1]}"
+  end unless respond_to?(:debugger)
 end
diff --git a/lib/rspec/core/version.rb b/lib/rspec/core/version.rb
index 97bbeb03ab..48fdae2048 100644
--- a/lib/rspec/core/version.rb
+++ b/lib/rspec/core/version.rb
@@ -1,7 +1,7 @@
 module RSpec # :nodoc:
   module Core # :nodoc:
     module Version # :nodoc:
-      STRING = '2.2.0'
+      STRING = '2.2.1'
     end
   end
 end
diff --git a/spec/autotest/rspec_spec.rb b/spec/autotest/rspec_spec.rb
index 5d542453d8..f71e16f992 100644
--- a/spec/autotest/rspec_spec.rb
+++ b/spec/autotest/rspec_spec.rb
@@ -39,6 +39,12 @@
         cmd.should match(/'#{File.expand_path(file_to_test)}'/)
       end
     end
+
+    it "gives '--tty' to #{Autotest::Rspec2::SPEC_PROGRAM}, not '--autotest'" do
+      cmd = rspec_autotest.make_test_cmd(@files_to_test)
+      cmd.should match(' --tty ')
+      cmd.should_not match(' --autotest ')
+    end
   end
 
   describe "mappings" do
diff --git a/spec/rspec/core/configuration_spec.rb b/spec/rspec/core/configuration_spec.rb
index 44435e6922..7b90ed3a72 100644
--- a/spec/rspec/core/configuration_spec.rb
+++ b/spec/rspec/core/configuration_spec.rb
@@ -503,13 +503,20 @@ def that_thing
       end
     end
 
-    describe "#debug=" do
-      it "is deprecated" do
-        RSpec.should_receive(:warn_deprecation)
+    describe "#debug=true" do
+      it "requires 'ruby-debug'" do
+        config.should_receive(:require).with('ruby-debug')
         config.debug = true
       end
     end
 
+    describe "#debug=false" do
+      it "does not require 'ruby-debug'" do
+        config.should_not_receive(:require).with('ruby-debug')
+        config.debug = false
+      end
+    end
+
     describe "#output=" do
       it "sets the output" do
         output = mock("output")
diff --git a/spec/rspec/core/kernel_extensions_spec.rb b/spec/rspec/core/kernel_extensions_spec.rb
index dd72a63dc0..dc59d7eecd 100644
--- a/spec/rspec/core/kernel_extensions_spec.rb
+++ b/spec/rspec/core/kernel_extensions_spec.rb
@@ -1,12 +1,9 @@
 require 'spec_helper'
 
 describe "extensions" do
-  describe "#debugger" do
-    it "warns if ruby-debug is not installed" do
-      object = Object.new
-      object.should_receive(:warn).with(/debugger .* ignored:\n.* ruby-debug/m)
-      object.stub(:require) { raise LoadError }
-      object.__send__ :method_missing, :debugger
+  describe "debugger" do
+    it "is defined on Kernel" do
+      Kernel.should respond_to(:debugger)
     end
   end
 end