问题
I've been looking for an answer to this for over a day now, and searched StackOverflow thoroughly.
I understand the conflict that's happening, and I should just uninstall the version of Rack I don't need, but here's the thing. I'm developing on Koding (http://koding.com) and I don't have access to system level gems.
Rails was working before, I installed the mongo gem, removed it, and installed mysql2 gem.
bash4.1$ rails
/usr/lib/ruby/site_ruby/1.8/rubygems.rb:233:in `activate': can't activate rack (~> 1.4.0, runtime) for ["actionpack-3.2.11", "railties-3.2.11"
], already activated rack-1.5.0 for ["rack-ssl-1.3.2", "railties-3.2.11"] (Gem::LoadError)
from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:249:in `activate'
from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:248:in `each'
from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:248:in `activate'
from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:249:in `activate'
from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:248:in `each'
from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:248:in `activate'
from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:1082:in `
from /usr/bin/rails:18
I've wiped my directory clean, tried using RVM, and still nothing. Any ideas?
Thanks!
回答1:
Use Bundler to resolve the Rack dependency according to the app Gemfile.
$ bundle exec rails
Otherwise, delete Rack 1.5.0 and retry.
$ gem uninstall rack
# select the proper version to delete
来源：https://stackoverflow.com/questions/14485219/cant-activate-rack-1-4-0-runtime-already-activated-rack-1-5-0