# Rbplusplus gem problem

**URL:** <https://www.ruby-forum.com/t/rbplusplus-gem-problem/137261>\
**Category:** Ruby\
**Created:** [May 10, 2008, 10:50pm UTC](https://www.ruby-forum.com/t/rbplusplus-gem-problem/137261 "2008-05-10T22:50:39Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Axel\_E](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7c8e57/32.png) [@Axel\_E](https://www.ruby-forum.com/u/Axel_E)\
**Post date:** [May 10, 2008, 10:50pm UTC](https://www.ruby-forum.com/t/rbplusplus-gem-problem/137261/1 "2008-05-10T22:50:39Z")

</div>

Dear all,

I am having some trouble getting the Rbplusplus gem  
[http://rbplusplus.rubyforge.org/rbplusplus/](http://rbplusplus.rubyforge.org/rbplusplus/)  
to work …  
I get an uninitialized constant error, which I suspect has something  
to do with the sequence of requiring the gems. But I can’t fix it,  
since I need the Extension class from the rbplusplus gem:

* * *

Ruby code:

require “rubygems”  
require ‘rbplusplus’  
include RbPlusPlus

working\_dir = File.expand\_path(File.dirname( **FILE** ) + “/generated”)  
p working\_dir  
Extension.new “first” do |e|  
e.sources “one.cpp”  
e.working\_dir = working\_dir  
end

* * *

C++ code one.cpp:

#include \<stdio.h\>

int main()  
{  
printf(“This is output from my first program!\n”);  
return 0;  
}

* * *

Output:

$ruby rb.rb  
“/home/axel/rbpp/generated”  
/var/lib/gems/1.8/gems/rbplusplus-0.1/lib/rbplusplus/extension.rb:173:in  
`prepare_working_dir': uninitialized constant RbPlusPlus::Extension::FileUtils (NameError) from /var/lib/gems/1.8/gems/rbplusplus-0.1/lib/rbplusplus/extension.rb:143:in `write’  
from  
/var/lib/gems/1.8/gems/rbplusplus-0.1/lib/rbplusplus/extension.rb:72:in  
`initialize' from rb.rb:8:in `new’  
from rb.rb:8

Thank you for your help,

Best regards,

Axel

---

<div class="post-metadata">

**Author:** ![Axel\_E](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7c8e57/32.png) [@Axel\_E](https://www.ruby-forum.com/u/Axel_E)\
**Post date:** [May 11, 2008, 12:17am UTC](https://www.ruby-forum.com/t/rbplusplus-gem-problem/137261/2 "2008-05-11T00:17:58Z")

</div>

Hello,

I’ve got the same bug.  
This is resolved by requiring the ‘fileutils’ in extension.rb.

Best regards,  
Thorsten

Am 10.05.2008 um 22:49 schrieb Axel E.:

---

<div class="post-metadata">

**Author:** ![Axel\_E](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7c8e57/32.png) [@Axel\_E](https://www.ruby-forum.com/u/Axel_E)\
**Post date:** [May 11, 2008, 12:43am UTC](https://www.ruby-forum.com/t/rbplusplus-gem-problem/137261/3 "2008-05-11T00:43:08Z")

</div>

-------- Original-Nachricht --------

> Datum: Sun, 11 May 2008 07:17:20 +0900  
> Von: Thorsten H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
> An: removed\_email\_address@domain.invalid  
> Betreff: Re: Rbplusplus gem problem

> > Dear all,
> > 
> > ```
> > from /var/lib/gems/1.8/gems/rbplusplus-0.1/lib/rbplusplus/ 
> > 
> > ```
> > 
> > –  
> > GMX startet [ShortView.de](http://ShortView.de). Hier findest Du Leute mit Deinen Interessen!  
> > Jetzt dabei sein: [http://www.shortview.de/?mc=sv\_ext\_mf@gmx](http://www.shortview.de/?mc=sv_ext_mf@gmx)

Thorsten,

thank you very much!

Best regards,

Axel