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"]
@@ -16,12 +20,16 @@ begin
   end
 
   Jeweler::RubyforgeTasks.new
-rescue LoadError
-  puts "Jeweler not available. Install it with: gem install jeweler"
 end
 
-desc "Run specs using RCov (uses mysql database adapter)"
-Spec::Rake::SpecTask.new(:coverage) do |t|
+begin
+  require "spec/rake/spectask"
+rescue LoadError
+  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']
@@ -31,9 +39,9 @@ Spec::Rake::SpecTask.new(:coverage) do |t|
     t.rcov_opts << '--text-summary'
     t.rcov_opts << '--sort' << 'coverage' << '--sort-reverse'
     t.rcov_opts << '--only-uncovered'
-end
+  end
 
-namespace :spec do
+  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|
@@ -45,14 +53,15 @@ namespace :spec do
           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' {} \\;}