# Can't activate gem because diff version already activated

**URL:** <https://www.ruby-forum.com/t/cant-activate-gem-because-diff-version-already-activated/142896>\
**Category:** Ruby\
**Created:** [July 13, 2008, 12:26am UTC](https://www.ruby-forum.com/t/cant-activate-gem-because-diff-version-already-activated/142896 "2008-07-13T00:26:30Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![levander](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ed655f/32.png) [@levander](https://www.ruby-forum.com/u/levander)\
**Post date:** [July 13, 2008, 12:26am UTC](https://www.ruby-forum.com/t/cant-activate-gem-because-diff-version-already-activated/142896/1 "2008-07-13T00:26:30Z")

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I’ve just done a ‘gem install junebug-wiki’. The 1st step to using  
junebug is to create a wiki instance. Trying to do that, I get this  
error:

# =========================================== levander@judas:~$ junebug testwiki /usr/local/lib/site\_ruby/1.8/rubygems.rb:142:in `activate': can't activate activesupport (= 1.4.4, runtime), already activated activesupport-2.1.0 (Gem::Exception) from /usr/local/lib/site_ruby/1.8/rubygems.rb:158:in`activate’ from /usr/local/lib/site\_ruby/1.8/rubygems.rb:157:in `each' from /usr/local/lib/site_ruby/1.8/rubygems.rb:157:in`activate’ from /usr/local/lib/site\_ruby/1.8/rubygems.rb:158:in `activate' from /usr/local/lib/site_ruby/1.8/rubygems.rb:157:in`each’ from /usr/local/lib/site\_ruby/1.8/rubygems.rb:157:in `activate' from /usr/local/lib/site_ruby/1.8/rubygems.rb:49:in`gem’ from /usr/bin/junebug:18

The problem is somehow related to my having multiple versions of the  
activesupport gem installed. I could just try removing the newer  
versions of all the gems I have duplicates installed for, but I’d really  
like to know what’s going on.

Here’s the output of ‘gem list’:

===========================================  
levander@judas:~$ gem list

\*\*\* LOCAL GEMS \*\*\*

# actionmailer (2.1.0) actionpack (2.1.0) activerecord (2.1.0, 1.15.6) activeresource (2.1.0) activesupport (2.1.0, 1.4.4) builder (2.1.2) camping (1.5) cgi\_multipart\_eof\_fix (2.5.0) daemons (1.0.10) fastthread (1.0.1) gem\_plugin (0.2.3) hoe (1.7.0) junebug-wiki (0.0.37) markaby (0.5) metaid (1.0) mongrel (1.1.2) passenger (2.0.1) rack (0.3.0) rails (2.1.0) rake (0.8.1) RedCloth (3.0.4) rubyforge (1.0.0) sqlite3-ruby (1.2.2) cponder@judas:~$ gem list | grep activesupport activesupport (2.1.0, 1.4.4)

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<div class="post-metadata">

**Author:** ![levander](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ed655f/32.png) [@levander](https://www.ruby-forum.com/u/levander)\
**Post date:** [September 7, 2008, 10:49pm UTC](https://www.ruby-forum.com/t/cant-activate-gem-because-diff-version-already-activated/142896/2 "2008-09-07T22:49:25Z")

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Levander Thomas wrote:

> I’ve just done a ‘gem install junebug-wiki’. The 1st step to using  
> junebug is to create a wiki instance. Trying to do that, I get this  
> error:
> 
> ===========================================  
> levander@judas:~$ junebug testwiki  
> /usr/local/lib/site\_ruby/1.8/rubygems.rb:142:in `activate’: can’t  
> activate activesupport (= 1.4.4, runtime), already activated

I’ve just had a similar problem with hobo - solved by  
sudo gem uninstall rails -v 2.1.1  
sudo gem install rails -v 2.1.0

Not tried having the 2 in parallel - not sure that would be a good idea.  
I think you can freeze your version so that you have a local version of  
rails just for this project.  
Hope it helps - I’m pretty ignorant about this stuff!