Setting EDITOR environment variable?

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Load .pdf file: pdf = PDF.read 'sample.pdf'
2. Try to edit: pdf.pages[2].edit
3. Error occured:
>>> pdf.pages[2].edit
NoMethodError: undefined method `edit' for nil:NilClass
        from (irb):2
        from C:/Ruby192/lib/ruby/gems/1.9.1/gems/origami-1.2.3/bin/pdfsh:12:in `<top (required)>'
        from C:/Ruby192/bin/pdfsh:19:in `load'
        from C:/Ruby192/bin/pdfsh:19:in `<main>'

What is the expected output? What do you see instead?
Possibility to edit page raw contents, but error occured instead.

What version of the product are you using? On what operating system?
Ruby 1.9.2-p290, Origami 1.2.3, Windows 7 Enterprise x64

Please provide any additional information below.
In GettingStarted guide said that "the EDITOR environment variable may need to 
be set up", but I don't know how to do that. I'm new to Ruby...
I tried to read all ReadMe-like files in ORIGAMI folder, but there is no 
information about setting EDITOR environment variable. Internet searh also 
doesn't help, Origami's PDF "origami-cheatsheet-1.0.0-beta2.pdf" too... I 
assuming that this feature is un-documented. :(
Can I ask for help here, please?

Thanks in advance.

Kind regards,
Stole

Original issue reported on code.google.com by [email protected] on 26 Oct 2011 at 12:30