Use `abort(message)` instead of `puts` and `exit`

lib/rdoc/ri/driver.rb

@@ -1554,8 +1554,7 @@ or the PAGER environment variable.
     begin
       require 'webrick'
     rescue LoadError
-      puts "webrick is not found. You may need to `gem install webrick` to install webrick."
-      exit
+      abort "webrick is not found. You may need to `gem install webrick` to install webrick."
     end
 
     server = WEBrick::HTTPServer.new :Port => @server

lib/rdoc/servlet.rb

@@ -7,8 +7,7 @@ require 'json'
 begin
   require 'webrick'
 rescue LoadError
-  puts "webrick is not found. You may need to `gem install webrick` to install webrick."
-  exit
+  abort "webrick is not found. You may need to `gem install webrick` to install webrick."
 end
 
 ##

lib/rubygems/server.rb

@@ -431,8 +431,7 @@ div.method-source-code pre { color: #ffdead; overflow: hidden; }
     begin
       require 'webrick'
     rescue LoadError
-      puts "webrick is not found. You may need to `gem install webrick` to install webrick."
-      exit
+      abort "webrick is not found. You may need to `gem install webrick` to install webrick."
     end
 
     Gem::RDoc.load_rdoc

lib/un.rb

@@ -329,8 +329,7 @@ def httpd
     begin
       require 'webrick'
     rescue LoadError
-      puts "webrick is not found. You may need to `gem install webrick` to install webrick."
-      exit
+      abort "webrick is not found. You may need to `gem install webrick` to install webrick."
     end
     opt = options[:RequestTimeout] and options[:RequestTimeout] = opt.to_i
     [:Port, :MaxClients].each do |name|