Hi, I'm attempting to use the RParsec gem under MacRuby, but am getting a NoMethodError when it loads. I've create a test file that simply adds my local gem directory to the front of the library search path and then calls "require 'rparsec'". This file runs fine under Ruby 1.9, but produces the following error when called from MacRuby 0.4. /Users/ehynes/Test/Gems/rparsec/parser.rb:32:in `block in init': super: no superclass method `initialize:' for RParsec::ValueParser:RParsec::ValueParser (NoMethodError) from /Users/ehynes/Test/Gems/rparsec/parsers.rb:621:in `new' from /Users/ehynes/Test/Gems/rparsec/parsers.rb:621:in `<module:RParsec>' from /Users/ehynes/Test/Gems/rparsec/parsers.rb:3:in `<top (required)>' from /Users/ehynes/Test/Gems/rparsec.rb:3:in `require' from /Users/ehynes/Test/Gems/rparsec.rb:3:in `block in <top (required)>' from /Users/ehynes/Test/Gems/rparsec.rb:2:in `each' from /Users/ehynes/Test/Gems/rparsec.rb:2:in `<top (required)>' from AbcParser.rb:2:in `require' from AbcParser.rb:2:in `<main>' The method with the error in the Parser class is: def self.init(*vars) parser_checker = {} vars.each_with_index do |var, i| name = var.to_s parser_checker[i] = var if name.include?('parser') && ! name.include?('parsers') end define_method(:initialize) do |*params| ---> super() # <--- line 32 vars.each_with_index do |var, i| param = params[i] if parser_checker.include? i TypeChecker.check_arg_type Parser, param, self, i end instance_variable_set("@"+var.to_s, param) end end end Any ideas as to why Ruby can call super in the above method, but MacRuby can't? Is there a fix or workaround that I could use? An alternate parser? Thanks, Ed P.S. I did have to change one line in the RParsec parser.rb file to get it to run under Ruby 1.9, replacing a ':' with a 'then' in a case statement. $ diff parser_original.rb parser.rb 881c881 < case c when String: c[0] else c end --- > case c when String then c[0] else c end # ':' replaced with 'then'