add more fields to ThreadedCommand

lib/rscons/threaded_command.rb

@@ -18,11 +18,23 @@ module Rscons
     #   output if the Environment's echo mode is :short.
     attr_reader :short_description
 
+    # @return [Hash]
+    #   Environment Hash to pass to Kernel#system.
+    attr_reader :system_env
+
+    # @return [Hash]
+    #   Options Hash to pass to Kernel#system.
+    attr_reader :system_options
+
     # @return [Hash]
     #   Field for Rscons to store the build operation while this threaded
     #   command is executing.
     attr_accessor :build_operation
 
+    # @return [Thread]
+    #   The thread waiting on this command to terminate.
+    attr_accessor :thread
+
     # Create a ThreadedCommand object.
     #
     # @param command [Array<String>]
@@ -35,10 +47,16 @@ module Rscons
     # @option options [String] :short_description
     #   Short description of the command. This will be printed to standard
     #   output if the Environment's echo mode is :short.
+    # @option options [Hash] :system_env
+    #   Environment Hash to pass to Kernel#system.
+    # @option options [Hash] :system_options
+    #   Options Hash to pass to Kernel#system.
     def initialize(command, options = {})
       @command = command
       @builder_info = options[:builder_info]
       @short_description = options[:short_description]
+      @system_env = options[:system_env]
+      @system_options = options[:system_options]
     end
 
   end