core: keep process group for SSH childprocess

lib/vagrant/util/ssh.rb

@@ -173,6 +173,13 @@ module Vagrant
         LOGGER.info("Executing SSH in subprocess: #{command_options.inspect}")
         process = ChildProcess.build("ssh", *command_options)
         process.io.inherit!
+
+        # This is to workaround issue #69 on ChildProcess. This will
+        # be removed at some point.
+        if process.kind_of?(ChildProcess::Unix::Process)
+          process.keep_pgid = true if process.respond_to?(:keep_pgid=)
+        end
+
         process.start
         process.wait
         return process.exit_code

vagrant.gemspec

@@ -15,7 +15,7 @@ Gem::Specification.new do |s|
   s.rubyforge_project         = "vagrant"
 
   s.add_dependency "bundler", "~> 1.5.2"
-  s.add_dependency "childprocess", "~> 0.4.1"
+  s.add_dependency "childprocess", "~> 0.4.2"
   s.add_dependency "erubis", "~> 2.7.0"
   s.add_dependency "i18n", "~> 0.6.0"
   s.add_dependency "listen", "~> 2.4.0"