Ruby blank environment scope for execution - ruby

Question

I'm currently developing a framework that basically executes another application, e.g. rails within the context of another ruby program. My initial attempt was simply to boot the app like this:
def load_app!
# Load the rails application
require './config/application'
# Initialize the rails application
#app = App::Application.initialize!
end
Problem here, is that the framework's requires conflict with the loaded application so the initialize! call never works although it would in a normal ruby program.
So my question is, if anyone knows a method to basically scope this calls into a unit that behaves like a blank RVM environment. So basically a behavior like this:
require 'json'
puts JSON.generate({:name => "test"})
blank_environment do
puts JSON.generate({:name => "test"})
#=> uninitialized constant JSON
require 'json'
puts JSON.generate({:name => "test"})
end
It's not done with undefining or unloading the currently loaded constants because I don't know all of them because I'm using gems that have other dependencies again.
So is there a cool way? Or any other way to handle this?
UPDATE:
Just came across an idea. Why is ruby's require method always requiring for the global scope? Wouldn't it be a very nice feature to actually scope the loaded modules under the the current module?
module ScopeA
require 'json' #> adds support for ScopeA::JSON
# due to normal ruby scoping everything can be called like normal in here
JSON.parse("something")
end
# JSON should not be available here
module ScopeB
require 'yaml'
YAML.parse("something") # but no JSON, of course
end
Doesn't something like this exist? include already has to know the constants...
Thanks in advance!

Answer 1

Well, after some more research it really doesn't seem possible the way I need it.
I now implemented a basic version using distributed ruby, which doesn't quite satisfy me:
require 'drb/drb'
URI = "druby://localhost:8787"
# Blank environment
pid = fork do
Signal.trap("INT") { puts "Stopping Server.."; exit }
class Application
def call(env)
[200,{},""]
end
end
DRb.start_service(URI, Application.new)
DRb.thread.join
end
# Working environment
DRb.start_service
app = DRbObject.new_with_uri(URI)
puts app.call({})
Process.kill("INT", pid)
Process.wait
If anyone comes up with a better approach, it's highly appreciated!