Just get the flag names

lib/vagrant.rb

@@ -20,9 +20,6 @@ module Vagrant
   # outside of command implementations to the local option
   # parser instances in use
   class OptionParser < ::OptionParser
-
-    attr_reader :flags
-
     def initialize(*_)
       super
       Vagrant.default_cli_options.each do |opt_proc|

plugins/commands/serve/service/command_service.rb

@@ -42,7 +42,7 @@ module VagrantPlugins
           }.map { |o|
             Hashicorp::Vagrant::Sdk::Command::Flag.new(
               description: o.desc.join(" "),
-              long_name: o.long.first,
+              long_name: o.switch_name,
               short_name: o.short.first,
               type: o.is_a?(OptionParser::Switch::NoArgument) ?
                 Hashicorp::Vagrant::Sdk::Command::Flag::Type::BOOL :
@@ -50,9 +50,6 @@ module VagrantPlugins
             )
           }
 
-          # Clean our option data out of the thread
-          Thread.current.thread_variable_set(:command_options, nil)
-
           Hashicorp::Vagrant::Sdk::Command::FlagsResp.new(
             flags: flags
           )