I have Mac OS X 10.6.2 with default Ruby 1.8.7. I installed Ruby 1.8.6 thourgh RVM (rvm install 1.8.6). While I run my tests with Ruby 1.8.6 I get error:
dyld: NSLinkModule() error dyld: Symbol not found: _DestroyConstitute Referenced from: /Users/snowak/.rvm/gems/ruby-1.8.6-p383/gems/rmagick-2.12.2/lib/RMagick2.bundle Expected in: flat namespace in /Users/snowak/.rvm/gems/ruby-1.8.6-p383/gems/rmagick-2.12.2/lib/RMagick2.bundle rake aborted! Command failed with status (): [/Users/snowak/.rvm/rubies/ruby-1.8.6-p383/...]
And test suite ends up. What is wrong with this Ruby instalation? In Ruby 1.8.7 all test are passed.
Which version of ImageMagick do you have installed? If you have 6.5.7 or higher installed, you need to have 2.13 or higher of rmagick
http://rubyforge.org/forum/forum.php?thread_id=46689&forum_id=32
At the time I'm writing this, I couldn't install 2.13 via the gem command, only 2.12.2. So just download the gem directly and install the file:
wget http://rubyforge.org/frs/download.php/68155/rmagick-2.13.0.gem
gem install rmagick-2.13.0.gem