We should use stdout to print greeting message in attach mode because gksudo swallows stderr.

Author: equivalence1

bin/gdb_wrapper

@@ -72,7 +72,7 @@ options.gems_to_include.each do |gem_path|
 end
 
 require 'ruby-debug-ide/greeter'
-Debugger::print_greeting_msg(nil, nil)
+Debugger::print_greeting_msg($stdout, nil, nil)
 
 require 'ruby-debug-ide/attach/util'
 require 'ruby-debug-ide/attach/native_debugger'

lib/ruby-debug-ide.rb

@@ -111,7 +111,7 @@ def start_control(host, port, notify_dispatcher)
           # "localhost" and nil have problems on some systems.
           host ||= '127.0.0.1'
           server = TCPServer.new(host, port)
-          print_greeting_msg(host, port)
+          print_greeting_msg($stderr, host, port)
           notify_dispatcher(port) if notify_dispatcher
           while (session = server.accept)
             $stderr.puts "Connected from #{session.peeraddr[2]}" if Debugger.cli_debug

lib/ruby-debug-ide/greeter.rb

@@ -10,7 +10,7 @@
 module Debugger
 
   class << self
-    def print_greeting_msg(host, port)
+    def print_greeting_msg(stream, host, port)
       base_gem_name = if defined?(JRUBY_VERSION) || RUBY_VERSION < '1.9.0'
                         'ruby-debug-base'
                       elsif RUBY_VERSION < '2.0.0'
@@ -33,7 +33,7 @@ def print_greeting_msg(host, port)
 
       msg = "Fast Debugger (ruby-debug-ide #{IDE_VERSION}, #{base_gem_name} #{VERSION}, file filtering is #{file_filtering_support})" + listens_on
 
-      $stderr.printf msg
+      stream.printf msg
     end
   end