# Gem and ruby extension **URL:** \ **Category:** Ruby\ **Created:** [December 27, 2005, 9:36pm UTC](https://www.ruby-forum.com/t/gem-and-ruby-extension/51193 "2005-12-27T21:36:48Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![giom](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/e56c9b/32.png) [@giom](https://www.ruby-forum.com/u/giom)\ **Post date:** [December 27, 2005, 9:36pm UTC](https://www.ruby-forum.com/t/gem-and-ruby-extension/51193/1 "2005-12-27T21:36:48Z")
I created a gem for a ruby C extension. Compiling the gem and installation goes find. When I try to run the test I get the following error: [gus@comp ~]$ sudo ruby /usr/lib/ruby/gems/1.8/gems/Rulog-0.1.0/test/rulog.rb Loaded suite /usr/lib/ruby/gems/1.8/gems/Rulog-0.1.0/test/rulog Started .ruby: symbol lookup error: /usr/lib/ruby/gems/1.8/gems/Rulog-0.1.0/lib/rulog.so: undefined symbol: rb\_mark But, if I specify an include directory to ruby, it work: [gus@comp ~]$ sudo ruby -I /usr/lib/ruby/gems/1.8/gems/Rulog-0.1.0/lib /usr/lib/ruby/gems/1.8/gems/Rulog-0.1.0/test/rulog.rb Loaded suite /usr/lib/ruby/gems/1.8/gems/Rulog-0.1.0/test/rulog Started … Finished in 2.341459 seconds. 4 tests, 38 assertions, 0 failures, 0 errors Duh! Why can’t it load rulog.so in the first case? The platform is ruby 1.8.2 (2004-12-25) [i586-linux-gnu]. Any idea, pointers? Guillaume. ---
**Author:** ![giom](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/e56c9b/32.png) [@giom](https://www.ruby-forum.com/u/giom)\ **Post date:** [December 27, 2005, 10:33pm UTC](https://www.ruby-forum.com/t/gem-and-ruby-extension/51193/2 "2005-12-27T22:33:18Z")
Guillaume M. wrote: > Duh! Why can’t it load rulog.so in the first case? The platform is ruby > 1.8.2 (2004-12-25) [i586-linux-gnu]. Ruby is able to find libraries installed via RubyGems only after the rubygem library is loaded. You can accomplish in several ways, including setting an environment variable (RUBYOPT=rubygems), including -rubygems on your ruby command line, or even putting a ‘require “rubygems”’ in your source code. See [http://docs.rubygems.org/read/chapter/3#page70](http://docs.rubygems.org/read/chapter/3#page70) for details. – – Jim W. ---
**Author:** ![giom](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/e56c9b/32.png) [@giom](https://www.ruby-forum.com/u/giom)\ **Post date:** [December 27, 2005, 11:40pm UTC](https://www.ruby-forum.com/t/gem-and-ruby-extension/51193/3 "2005-12-27T23:40:40Z")
On Wed, 2005-12-28 at 06:33 +0900, Jim W. wrote: > Guillaume M. wrote: > > > Duh! Why can’t it load rulog.so in the first case? The platform is ruby > > 1.8.2 (2004-12-25) [i586-linux-gnu]. > > Ruby is able to find libraries installed via RubyGems only after the > rubygem library is loaded. You can accomplish in several ways, > including setting an environment variable (RUBYOPT=rubygems), including > -rubygems on your ruby command line, or even putting a ‘require > “rubygems”’ in your source code. See > [http://docs.rubygems.org/read/chapter/3#page70](http://docs.rubygems.org/read/chapter/3#page70) for details. Thanks for you quick answer. But I forgot to mention that I already have the RUBYOPT variable set: [gus@comp ruby-1.8.2]$ echo $RUBYOPT -rrubygems [gus@comp ruby-1.8.2]$ grep RUBY ~/.bashrc RUBYOPT=“-rrubygems” export RUBYOPT What strikes me as odd in this case is that it gives the right path of the library to load (somewhere in /usr/lib/ruby/gems) but fails to load it. If the path is added to $: (in the second example), then it loads properly. Guillaume. ---
**Author:** ![giom](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/e56c9b/32.png) [@giom](https://www.ruby-forum.com/u/giom)\ **Post date:** [December 28, 2005, 2:20am UTC](https://www.ruby-forum.com/t/gem-and-ruby-extension/51193/4 "2005-12-28T02:20:11Z")
On Wed, 2005-12-28 at 09:47 +0900, Une bévue wrote: > BEWARE, in your case you have TWO “r” ie : > -rrubygems Actually, both work. AFAIK, rubygems is the official name of the library but ubygems is also there so it looks good when using the -r options. ‘ruby -rubygems’ and ‘ruby -rrubygems’ are equivalent. Looking in /usr/lib/ruby I see: /usr/lib/ruby/site\_ruby/1.8/ubygems.rb /usr/lib/ruby/site\_ruby/1.8/rubygems.rb and $ cat /usr/lib/ruby/site\_ruby/1.8/ubygems.rb # This file allows for the running of rubygems with a nice # command line look-and-feel: ruby -rubygems foo.rb require ‘rubygems’ Guillaume. ---
**Author:** ![giom](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/e56c9b/32.png) [@giom](https://www.ruby-forum.com/u/giom)\ **Post date:** [December 28, 2005, 1:50am UTC](https://www.ruby-forum.com/t/gem-and-ruby-extension/51193/5 "2005-12-28T01:50:03Z")
Guillaume M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > [gus@comp ruby-1.8.2]$ echo $RUBYOPT > -rrubygems do you think this is right, because i’ve done : export RUBYOPT=rubygems (without de “-”) and, i’ve seen progs complaining about ubygems (without the “r”) BEWARE, in your case you have TWO “r” ie : -rrubygems _^^_\_\_\_\_\_\_ ---
**Author:** ![giom](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/e56c9b/32.png) [@giom](https://www.ruby-forum.com/u/giom)\ **Post date:** [December 28, 2005, 1:44am UTC](https://www.ruby-forum.com/t/gem-and-ruby-extension/51193/6 "2005-12-28T01:44:03Z")
On Wed, 2005-12-28 at 07:38 +0900, Guillaume M. wrote: > > [http://docs.rubygems.org/read/chapter/3#page70](http://docs.rubygems.org/read/chapter/3#page70) for details. > > What strikes me as odd in this case is that it gives the right path of > > the library to load (somewhere in /usr/lib/ruby/gems) but fails to load > > it. If the path is added to $: (in the second example), then it loads > > properly. My fault. rb\_mark doesn’t exists, rb\_gc\_mark is want I wanted. What confused me is that it doesn’t complain when the library is required, but when the call of this function is made. Sorry for the noise, Guillaume. ---
**Author:** ![giom](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/e56c9b/32.png) [@giom](https://www.ruby-forum.com/u/giom)\ **Post date:** [December 28, 2005, 8:54am UTC](https://www.ruby-forum.com/t/gem-and-ruby-extension/51193/7 "2005-12-28T08:54:08Z")
Guillaume M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Actually, both work. AFAIK, rubygems is the official name of the library > but ubygems is also there so it looks good when using the -r options. > ‘ruby -rubygems’ and ‘ruby -rrubygems’ are equivalent. thanks for your input that makes my setup clearer to me )) my prob with “ubygems” comes to the fact i’ve two Rubys : the default install on MacOS X /usr/bin/ruby and the darwinports one /opt/local/bin/ruby only the latest works with rubygems…