Rails Server Won't Run on OS X Lion

I'm a beginner programmer and I'm trying to get the rails server to run on OS X Lion. When I type "rails server" into the command line, I get this error:

/System/Library/Frame开发者_开发百科works/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:777:in `report_activate_error': Could not find RubyGem rails (>= 0) (Gem::LoadError)
from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:211:in `activate'
from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:1056:in `gem'
from /usr/bin/rails:18

What do you think a solution to the problem is? Any help you can provide would be greatly appreciated. Thanks!

You need to install the rails gem. You could probably do this by running bundle install inside that project.

Have you installed the Rails Gem?

gem install rails

Then do a gem list to see if Rails is in there.

It's also important that you be in the proper directory. So if you keep all of your apps in /apps/ make sure you are in /apps/my_app before calling the server command.

The Ruby bundled with OS X is too old for Rails 3.

I would recommended using 'rvm' to install the latest stable version of ruby-1.9.2-p260

Since installing ruby requires some compilation, make sure you have a gcc installed. You can install XCode to get an usable gcc.

To install rvm, you need bash, git and curl.

RVM: http://beginrescueend.com/

After that, you can use

gem install rails

Enjoy!

The Lion Server looks at a non-default path for the gem file

For example have a look at the first line of /usr/share/devicemgr/backend/devicemgrd:

#!/usr/bin/env GEM_HOME=/usr/share/devicemgr/webserver/gems GEM_PATH=/usr/share/devicemgr/webserver/gems RAILS_ENV=production /usr/bin/ruby

So to install the missing gems, make sure to install them at the required path:

sudo GEM_HOME=/usr/share/devicemgr/webserver/gems gem install rails