# Odd requirement behavior between two environments **URL:** \ **Category:** Ruby\ **Created:** [July 16, 2007, 8:50pm UTC](https://www.ruby-forum.com/t/odd-requirement-behavior-between-two-environments/109557 "2007-07-16T20:50:56Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![ian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/bb73d2/32.png) [@ian](https://www.ruby-forum.com/u/ian)\ **Post date:** [July 16, 2007, 8:50pm UTC](https://www.ruby-forum.com/t/odd-requirement-behavior-between-two-environments/109557/1 "2007-07-16T20:50:56Z")
I’m setting up a Ruby project on a new development machine and have run into some trouble getting my unit tests to run. Can any one suggest what the vital difference between these two machines might be, or what is causing the error? Esentially, my problem is that even though I have installed the ActiveRecord gem, I am unable to use it in a script. Old development machine where everything works: Ruby 1.8.4 Gems 0.8.11 ActiveRecord gem installed 1.15.2 Results of IRB session on the old development machine irb(main):001:0\> require ‘rubygems’ =\> true irb(main):002:0\> require\_gem ‘activerecord’ =\> true irb(main):003:0\> ActiveRecord =\> ActiveRecord Ok, so that looks good. I can require the gem & then IRB knows what ActiveRecord is. Great. New development machine where this doesn’t work Ruby 1.8.6 Gems 0.9.4 ActiveRecord gem installed 1.15.3 Results of IRB session on the new development machine irb(main):001:0\> require ‘rubygems’ =\> true irb(main):002:0\> gem ‘activerecord’ =\> true irb(main):003:0\> ActiveRecord NameError: uninitialized constant ActiveRecord from (irb):3 So, something is up. In line 2 I’m using the command newer command ‘gem’ instead of the depreciated ‘require\_gem’. But I get the same result even if I use the depreciated command. Any ideas? Something I forgot to install on this new machine? Or some weird configuration change I made on the old machine that I didn’t copy over. Thanks for any advice, Ian ---
**Author:** ![ian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/bb73d2/32.png) [@ian](https://www.ruby-forum.com/u/ian)\ **Post date:** [July 16, 2007, 9:12pm UTC](https://www.ruby-forum.com/t/odd-requirement-behavior-between-two-environments/109557/2 "2007-07-16T21:12:58Z")
On 7/16/07, Ian W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > irb(main):001:0\> require ‘rubygems’ > > Any ideas? Something I forgot to install on this new machine? Or some weird > configuration change I made on the old machine that I didn’t copy over. require\_gem / gem are not the same as require. They’re meant for locking gems to specific versions or making sure they exist, not loading libraries, e.g. gem “ruport”, “=1.0.1” Also, with that in mind note that gem names don’t always coincide with library names, so you actually will need to do this: require “rubygems” require “active\_record” In earlier versions of RubyGems, it was possible for the require\_gem command to autoload libraries, this is no longer the case. Hope that helps… -greg ---
**Author:** ![ian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/bb73d2/32.png) [@ian](https://www.ruby-forum.com/u/ian)\ **Post date:** [July 16, 2007, 9:16pm UTC](https://www.ruby-forum.com/t/odd-requirement-behavior-between-two-environments/109557/3 "2007-07-16T21:16:59Z")
On 7/17/07, Ian W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > =\> true > irb(main):003:0\> ActiveRecord > NameError: uninitialized constant ActiveRecord > from (irb):3 “gem” doesn’t perform an implicit require; it simply modifies $: to include the path to the gem. irb(main):001:0\> old = $:.dup =\> [“/usr/lib/ruby/site\_ruby/1.8”, “/usr/lib/ruby/site\_ruby/1.8/i686-linux”, “/usr/lib/ruby/site\_ruby”, “/usr/lib/ruby/1.8”, “/usr/lib/ruby/1.8/i686-linux”, “.”] irb(main):002:0\> require ‘rubygems’ =\> true irb(main):003:0\> gem ‘activerecord’ =\> true irb(main):004:0\> $: - old =\> [“/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.2/bin”, “/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib”, “/usr/lib/ruby/gems/1.8/gems/activesupport-1.3.1/bin”, “/usr/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib”] irb(main):005:0\> require ‘activerecord’ LoadError: no such file to load – activerecord from /usr/lib/ruby/site\_ruby/1.8/rubygems/custom\_require.rb:27:in `gem_original_require' from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require’ from (irb):5 irb(main):006:0\> require ‘active\_record’ #sheesh =\> true irb(main):007:0\> ActiveRecord =\> ActiveRecord martin ---
**Author:** ![ian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/bb73d2/32.png) [@ian](https://www.ruby-forum.com/u/ian)\ **Post date:** [July 16, 2007, 9:26pm UTC](https://www.ruby-forum.com/t/odd-requirement-behavior-between-two-environments/109557/4 "2007-07-16T21:26:01Z")
On 7/16/07 2:05 PM, “Gregory B.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > Results of IRB session on the new development machine > > instead of the depreciated ‘require\_gem’. But I get the same result even if > > -greg Thank you, that seems to have moved me forward. Ian