#<NoMethodError: No method 'size' on an instance of NilClass.>
An exception has occurred:
    No method 'size' on an instance of NilClass. (NoMethodError)

Backtrace:

euler:~/devel/rubinius brian$ ./shotgun/rubinius 
sirb(eval):000> class K; end
=> nil
sirb(eval):001> k = K.new
instruction_dt.gen:786: failed assertion `c->sp_ptr > c->fp_ptr + _int'

class MethodTable

  def public_names
    filter_names :public
  end

task :default => :spec

def newer?(file, cmp)
  File.exists?(cmp) and File.mtime(cmp) >= File.mtime(file)
end

=> ["bytecode/compiler", "bytecode/assembler", "bytecode/encoder", "sexp/simple_processor", "translation/normalize", "translation/local_scoping", "sexp/composite_processor", "translation/states", "sexp/exceptions", "bytecode/primitive_names"]
irb(main):025:0> files.each do |file|
irb(main):026:1* puts file
irb(main):027:1> puts `ruby ./bin/compare_assembly.rb lib/#{file}.rb`
irb(main):028:1> end

kernel/core/array.rb
=> r18
=> rubinius
--- /tmp/compare.2288.0 2007-05-14 22:14:00.000000000 -0700
+++ /tmp/compare2.2288.0        2007-05-14 22:14:01.000000000 -0700

def show_method(m)
  puts "\n[[ #{m.name} ]]"
  # puts m.assembly
  # p m.locals
  # m.literals.each do |lit|

Using Dir to move around the filesystem
-------------------
 - Dir.pwd and Dir.getwd return the current working directory
 - Dir.chdir can be used to change the working directory--temporary if a block is provided. Defaults to $HOME FAILED:
Equality expected for "/private/tmp/rubinius_mock_fs" and "/tmp/rubinius_mock_fs":