"bad file descriptor" in a call to console_size

in Windows, Ruby 1.9.3, RDoc 4.2.0, with this example input file, focusgroup.rb:

require 'focusgroup/pipeline'
require 'focusgroup/serviceversion'

running rdoc --debug focusgroup.rb produces:

Before reporting this, could you check that the file you're documenting
has proper syntax:

  c:/Ruby193/bin/ruby.exe -c focusgroup.rb

RDoc is not a full Ruby parser and will fail when fed invalid ruby programs.

The internal error was:

    (Errno::EBADF) Bad file descriptor

c:/Ruby193/lib/ruby/1.9.1/io/console/size.rb:16:in `winsize'
    c:/Ruby193/lib/ruby/1.9.1/io/console/size.rb:16:in `console_size'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/stats/normal.rb:29:in `print_file'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/stats.rb:81:in `add_file'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:347:in `parse_file'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:421:in `block in parse_files'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:419:in `map'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:419:in `parse_files'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:489:in `document'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/bin/rdoc:20:in `<top (required)>'
    c:/Ruby193/bin/rdoc:23:in `load'
    c:/Ruby193/bin/rdoc:23:in `<main>'
Bad file descriptor
c:/Ruby193/lib/ruby/1.9.1/io/console/size.rb:16:in `winsize'
    c:/Ruby193/lib/ruby/1.9.1/io/console/size.rb:16:in `console_size'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/stats/normal.rb:29:in `print_file'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/stats.rb:81:in `add_file'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:347:in `parse_file'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:421:in `block in parse_files'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:419:in `map'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:419:in `parse_files'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/lib/rdoc/rdoc.rb:489:in `document'
    c:/Ruby193/lib/ruby/gems/1.9.1/gems/rdoc-4.2.0/bin/rdoc:20:in `<top (required)>'
    c:/Ruby193/bin/rdoc:23:in `load'
    c:/Ruby193/bin/rdoc:23:in `<main>'

c:/Ruby193/bin/ruby.exe -c focusgroup.rb produces:

Syntax OK

Start in lib/rdoc/stats/normal.rb at the print_file call to console_size, then compare it with the failing winsize call in Ruby's io/console/size.rb. Reproduce with the supplied focusgroup.rb input and verify that rdoc --debug completes without the Errno::EBADF error while the input remains syntax-valid.