Problem deploying simple ruby sinatra app on heroku - ruby

Question

I am new to ruby, git and heroku. I was trying to build a simple Hello World app and deploy it on heroku. I see the following error in the logs when I try to access the site using the heroku provided URL. Could you tell me what I am not doing right.
2011-07-03T01:15:06+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/rack-1.1.0/lib/rack/builder.rb:46:in `instance_eval'
2011-07-03T01:15:06+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/rack-1.1.0/lib/rack/builder.rb:46:in `initialize'
2011-07-03T01:15:06+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:1:in `new'
2011-07-03T01:15:06+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:1:in `<main>'
2011-07-03T01:15:06+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/rack/adapter/loader.rb:36:in `eval'
2011-07-03T01:15:06+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/controllers/controller.rb:175:in `load_rackup_config'
2011-07-03T01:15:06+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/rack/adapter/loader.rb:36:in `load'
2011-07-03T01:15:06+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/controllers/controller.rb:65:in `start'
2011-07-03T01:15:06+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/runner.rb:177:in `run_command'
2011-07-03T01:15:06+00:00 heroku[web.1]: Process exited
2011-07-03T01:15:07+00:00 heroku[web.1]: State changed from starting to crashed
config.ru file
require 'myapp2'
run Sinatra::Application
myapp2.rb
require 'rubygems'
require 'sinatra'
get '/' do
'Hello World'
end

Answer 1

You're missing the top of the stack trace, but it looks like the problem is the require.
In config.ru change
require 'myapp2'
to
require './myapp2'
or
require File.expand_path("../myapp2", __FILE__)
Ruby 1.9.2 no longer has the current directory in the load path, so require 'myapp2' isn't able to find your app file which is in the same directory.
If this is working on your local machine, but not on Heroku, then you're likely using a different version of Ruby, probably 1.8.7. It would be a good idea to install 1.9.2 locally so that you're using the same version in development and production. Alternatively you could change the Heroku stack you're using; have a look at the Heroku stack docs