Gracefully handle case where RSpec is not installed in Rakefile

Rakefile

@@ -1,9 +1,13 @@
 require "rubygems"
-require "spec/rake/spectask"
 
 begin
   require 'jeweler'
-
+rescue LoadError
+  desc "Install gem using sudo"
+  task(:install) do
+    $stderr.puts "Jeweler not available. `gem install jeweler` to install this gem"
+  end
+else
   Jeweler::Tasks.new do |s|
     s.name      = "arel"
     s.authors   = ["Bryan Helmkamp", "Nick Kallen"]
@@ -16,43 +20,48 @@ begin
   end
 
   Jeweler::RubyforgeTasks.new
+end
+
+begin
+  require "spec/rake/spectask"
 rescue LoadError
-  puts "Jeweler not available. Install it with: gem install jeweler"
-end
+  desc "Run specs"
+  task(:spec) { $stderr.puts '`gem install rspec` to run specs' }
+else
+  desc "Run specs using RCov (uses mysql database adapter)"
+  Spec::Rake::SpecTask.new(:coverage) do |t|
+    t.spec_files =
+      ["spec/connections/mysql_connection.rb"] +
+      FileList['spec/**/*_spec.rb']
 
-desc "Run specs using RCov (uses mysql database adapter)"
-Spec::Rake::SpecTask.new(:coverage) do |t|
-  t.spec_files =
-    ["spec/connections/mysql_connection.rb"] +
-    FileList['spec/**/*_spec.rb']
+    t.rcov = true
+    t.rcov_opts << '--exclude' << "spec,gems"
+    t.rcov_opts << '--text-summary'
+    t.rcov_opts << '--sort' << 'coverage' << '--sort-reverse'
+    t.rcov_opts << '--only-uncovered'
+  end
 
-  t.rcov = true
-  t.rcov_opts << '--exclude' << "spec,gems"
-  t.rcov_opts << '--text-summary'
-  t.rcov_opts << '--sort' << 'coverage' << '--sort-reverse'
-  t.rcov_opts << '--only-uncovered'
-end
-
-namespace :spec do
-  for adapter in %w[mysql sqlite3 postgresql]
-    desc "Run specs with the #{adapter} database adapter"
-    Spec::Rake::SpecTask.new(adapter) do |t|
-      t.libs << "#{File.dirname(__FILE__)}/vendor/rails/activerecord/lib"
-      t.libs << "#{File.dirname(__FILE__)}/spec"
-      t.spec_files =
-        ["spec/connections/#{adapter}_connection.rb"] +
-        ["spec/schemas/#{adapter}_schema.rb"] +
-        FileList['spec/**/*_spec.rb']
+  namespace :spec do
+    for adapter in %w[mysql sqlite3 postgresql]
+      desc "Run specs with the #{adapter} database adapter"
+      Spec::Rake::SpecTask.new(adapter) do |t|
+        t.libs << "#{File.dirname(__FILE__)}/vendor/rails/activerecord/lib"
+        t.libs << "#{File.dirname(__FILE__)}/spec"
+        t.spec_files =
+          ["spec/connections/#{adapter}_connection.rb"] +
+          ["spec/schemas/#{adapter}_schema.rb"] +
+          FileList['spec/**/*_spec.rb']
+      end
     end
   end
+
+  desc "Run specs with mysql and sqlite3 database adapters (default)"
+  task :spec => ["check_dependencies", "spec:sqlite3", "spec:mysql", "spec:postgresql"]
+
+  desc "Default task is to run specs"
+  task :default => :spec
 end
 
-desc "Run specs with mysql and sqlite3 database adapters (default)"
-task :spec => ["check_dependencies", "spec:sqlite3", "spec:mysql", "spec:postgresql"]
-
-desc "Default task is to run specs"
-task :default => :spec
-
 desc 'Removes trailing whitespace'
 task :whitespace do
   sh %{find . -name '*.rb' -exec sed -i '' 's/ *$//g' {} \\;}