Rails rake gems:install

Rails rake gems:install

With ruby on rails there's a great little task rake gems:install which will install any required gems for your app, which you have specified in your configuration environment.

The problem is your plugins and models will most likely require those gems, and the rake task will load the environment, thus load the plugins and models, etc. before it installs the require gems.

A classic catch22 scenario.

There is no real purpose to load the environment at all, but commenting out that line will bring up various other errors, instead you can let it load the first part of the environment you need, rescue the inevitable exception, then it will install the gems as required

So in rails/lib/gems.rake you will see:
namespace :gems do
  task :base do
    $gems_rake_task = true
    require 'rubygems'
    require 'rubygems/gem_runner'
    begin
      Rake::Task[:environment].invoke
    rescue

    end
  end
  ...
end

Replace:
      Rake::Task[:environment].invoke

With:
    begin
      Rake::Task[:environment].invoke
    rescue
    end

And things work like you would except.

Obviously not the ideal solution, but it gets the job done quickly