# Rubystandard library question

**URL:** <https://www.ruby-forum.com/t/rubystandard-library-question/100735>\
**Category:** Rails\
**Created:** [February 3, 2006, 8:11pm UTC](https://www.ruby-forum.com/t/rubystandard-library-question/100735 "2006-02-03T20:11:32Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![James\_BSByrne](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/838e76/32.png) [@James\_BSByrne](https://www.ruby-forum.com/u/James_BSByrne)\
**Post date:** [February 3, 2006, 8:11pm UTC](https://www.ruby-forum.com/t/rubystandard-library-question/100735/1 "2006-02-03T20:11:32Z")

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I have a problem getting find.rb and fileutils.rb to coexist in the  
same script. When I require both I get the following:

/usr/lib/ruby/1.8/find.rb:36:in `dup': can't dup NilClass (TypeError) from /usr/lib/ruby/1.8/find.rb:36:in`find’  
from /usr/lib/ruby/1.8/find.rb:36:in `find’

I googled for this problem and did not come across any place (in  
English at least) that covered it. I am still ploughing through  
the tutorials on Ruby and Rails and, given the extraordinarily high  
amount of traffic on the ruby list, was wondering if anyone here  
could tell me what I am doing wrong. Do I have to provide a  
namespace? How?

Regards,  
Jim

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<div class="post-metadata">

**Author:** ![James\_BSByrne](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/838e76/32.png) [@James\_BSByrne](https://www.ruby-forum.com/u/James_BSByrne)\
**Post date:** [February 3, 2006, 10:45pm UTC](https://www.ruby-forum.com/t/rubystandard-library-question/100735/2 "2006-02-03T22:45:13Z")

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On Feb 3, 2006, at 11:08 AM, James B. Byrne wrote:

> I have a problem getting find.rb and fileutils.rb to coexist in the  
> same script.

That should not be a problem. Likely you are doing something wrong.

> When I require both I get the following:
> 
> /usr/lib/ruby/1.8/find.rb:36:in `dup': can't dup NilClass (TypeError) from /usr/lib/ruby/1.8/find.rb:36:in `find’  
> from /usr/lib/ruby/1.8/find.rb:36:in `find’

If you don’t pass a nil value into Find::find you won’t have this error.

What is the full backtrace including a small script to illustrate the  
problem.

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