Heroku not using the specified Ruby 1.9.3

Question

Upgrading to Mongoid 3 and Ruby 1.9.3. Trying to use Ruby 1.9.3 on Heroku Cedar Stack. I have added the below to the top of my Gemfile:

source 'http://rubygems.org'
ruby "1.9.3"

Pushing to Heroku, it seemed to be working

-----> Heroku receiving push
-----> Ruby/Rails app detected
-----> Using Ruby version: ruby-1.9.3
-----> Installing dependencies using Bundler version 1.2.0.rc.2

However my app is breaking as it requires Ruby 1.9.3. The error is coming as:

TypeError: can't convert Array into String
from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/node.rb:214:in getaddrinfo'
from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/node.rb:214:ininitialize'

My path has bin at the beginning as suggested here

PATH => bin:vendor/bundle/ruby/1.9.1/bin:/usr/local/bin:/usr/bin:/bin

Any idea what could be wrong?

UPDATE:

Mongoid.yml

development: 
  sessions: 
    default: 
      database: myapp_development
      hosts: 
        - "localhost:27017"
      max_retries_on_connection_failure: 3
production: 
  sessions: 
    default: 
      database: "<%= ENV['MONGOHQ_DATABASE'] %>"
      hosts: 
        - 
          - "<%= ENV['MONGOHQ_URL1'] %>:<%= ENV['MONGOHQ_PORT'] %>"
        - 
          - "<%= ENV['MONGOHQ_URL2'] %>:<%= ENV['MONGOHQ_PORT'] %>"
      max_retries_on_connection_failure: 10
      password: "<%= ENV['MONGOHQ_PASSWORD'] %>"
      read: !ruby/symbol secondary
      username: "<%= ENV['MONGOHQ_USERNAME'] %>"

Heroku Push Output:

-----> Heroku receiving push
-----> Ruby/Rails app detected
-----> Using Ruby version: ruby-1.9.3
-----> Installing dependencies using Bundler version 1.2.0.rc.2
       Running: bundle install --without development:test --path vendor/bundle --binstubs bin/ --deployment
       Fetching gem metadata from http://rubygems.org/......
       Fetching gem metadata from http://rubygems.org/..
       Fetching https://github.com/dementrock/sunspot_mongoid.git
       Using rake (0.9.2.2)
       Using log4r (1.1.10)
       Using XMLCanonicalizer (1.0.1)
       Using multi_json (1.0.4)
       Using activesupport (3.1.3)
       Using builder (3.0.0)
       Using i18n (0.6.0)
       Using activemodel (3.1.3)
       Using erubis (2.7.0)
       Using rack (1.3.5)
       Using rack-cache (1.2)
       Using rack-mount (0.8.3)
       Using rack-test (0.6.1)
       Using hike (1.2.1)
       Using tilt (1.3.3)
       Using sprockets (2.0.4)
       Using actionpack (3.1.3)
       Installing mime-types (1.19)
       Using polyglot (0.3.3)
       Using treetop (1.4.10)
       Using mail (2.3.3)
       Using actionmailer (3.1.3)
       Using arel (2.2.3)
       Using tzinfo (0.3.33)
       Using activerecord (3.1.3)
       Using activeresource (3.1.3)
       Using addressable (2.2.8)
       Installing excon (0.15.5)
       Using formatador (0.2.3)
       Using net-ssh (2.5.2)
       Using net-scp (1.0.4)
       Installing nokogiri (1.5.5) with native extensions
       Using ruby-hmac (0.4.0)
       Installing fog (1.5.0)
       Installing asset_sync (0.4.2)
       Installing bson (1.6.4)
       Installing bson_ext (1.6.4) with native extensions
       Using carmen (0.2.7)
       Using carrierwave (0.5.8)
       Installing moped (1.2.0)
       Installing origin (1.0.6)
       Installing mongoid (3.0.4)
       Installing carrierwave-mongoid (0.1.0)
       Installing clockwork (0.4.1)
       Using coffee-script-source (1.3.3)
       Using execjs (1.4.0)
       Using coffee-script (2.2.0)
       Using rack-ssl (1.3.2)
       Installing json (1.7.4) with native extensions
       Using rdoc (3.12)
       Using thor (0.14.6)
       Using railties (3.1.3)
       Using coffee-rails (3.1.1)
       Installing daemons (1.1.9)
       Using delayed_job (3.0.3)
       Using delayed_job_active_record (0.3.2)
       Using eventmachine (0.12.10)
       Using exceptional (2.0.32)
       Using multipart-post (1.1.5)
       Using faraday (0.7.6)
       Using fastercsv (1.5.5)
       Using haml (3.1.6)
       Using jquery-rails (1.0.19)
       Using kaminari (0.13.0)
       Installing systemu (2.5.2)
       Installing macaddr (1.6.1)
       Using net-http-digest_auth (1.2.1)
       Using net-http-persistent (1.9)
       Using webrobots (0.0.13)
       Using mechanize (2.0.1)
       Installing mongo (1.6.4)
       Using mongoid_spacial (0.2.16)
       Using multi_xml (0.4.4)
       Using mysql2 (0.3.11)
       Using net-ldap (0.2.2)
       Installing newrelic_moped (0.0.3)
       Installing newrelic_rpm (3.4.1)
       Using oa-core (0.3.0)
       Using rest-client (1.6.7)
       Using oa-basic (0.3.0)
       Using pyu-ruby-sasl (0.0.3.3)
       Using rubyntlm (0.1.1)
       Using uuid (2.3.5)
       Using oa-enterprise (0.3.0)
       Using oa-more (0.3.0)
       Using oauth (0.4.6)
       Using oauth2 (0.5.2)
       Using oa-oauth (0.3.0)
       Installing ruby-openid (2.2.0)
       Using rack-openid (1.3.1)
       Using ruby-openid-apps-discovery (1.2.0)
       Using oa-openid (0.3.0)
       Using omniauth (0.3.0)
       Installing pg (0.14.0) with native extensions
       Using pr_geohash (1.0.0)
       Using bundler (1.2.0.rc.2)
       Using rails (3.1.3)
       Using recaptcha (0.3.4)
       Using rmagick (2.13.1)
       Using rpm_contrib (2.1.11)
       Using rsolr (1.0.8)
       Using ruby-prof (0.11.2)
       Installing sass (3.2.0)
       Using sass-rails (3.1.4)
       Using sitemap_generator (2.1.8)
       Installing sunspot (1.3.3)
       Installing sunspot_rails (1.3.3)
       Using sunspot_mongoid (0.4.1) from https://github.com/dementrock/sunspot_mongoid.git (at master)
       Installing thin (1.4.1) with native extensions
       Using typhoeus (0.3.3)
       Using uglifier (1.2.4)
       Using validatable (1.6.7)
       Your bundle is complete! It was installed into ./vendor/bundle
       Post-install message from newrelic_rpm:
       PLEASE NOTE:
       Developer Mode is now a Rack middleware.
       Developer Mode is no longer available in Rails 2.1 and earlier.
       However, starting in version 2.12 you can use Developer Mode in any
       Rack based framework, in addition to Rails.  To install developer mode
       in a non-Rails application, just add NewRelic::Rack::DeveloperMode to
       your middleware stack.
       If you are using JRuby, we recommend using at least version 1.4 or
       later because of issues with the implementation of the timeout library.
       Refer to the README.md file for more information.
       Please see http://github.com/newrelic/rpm/blob/master/CHANGELOG
       for a complete description of the features and enhancements available
       in version 3.4 of the Ruby Agent.

       Cleaning up the bundler cache.
-----> Writing config/database.yml to read from DATABASE_URL
-----> Preparing app for Rails asset pipeline
       Detected manifest.yml, assuming assets were compiled locally
-----> Rails plugin injection
       Injecting rails_log_stdout
       Injecting rails3_serve_static_assets
-----> Discovering process types
       Procfile declares types      -> clock, web, worker
       Default types for Ruby/Rails -> console, rake
-----> Compiled slug size is 36.3MB
-----> Launching... done, v318
-----> Deploy hooks scheduled, check output in your logs
       http://myapp.herokuapp.com deployed to Heroku

The server logs:

/app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/node.rb:214:in getaddrinfo' /app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/node.rb:214:in initialize' /app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/cluster.rb:53:in new' /app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/cluster.rb:53:in block in initialize' /app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/cluster.rb:53:in map' /app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/cluster.rb:53:in initialize' /app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/session.rb:183:in new' /app/vendor/bundle/ruby/1.9.1/gems/moped-1.2.0/lib/moped/session.rb:183:in initialize' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/sessions/factory.rb:64:in new' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/sessions/factory.rb:64:in create_session' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/sessions/factory.rb:43:in default' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/sessions.rb:109:in default' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/sessions.rb:378:in __session__' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/sessions.rb:213:in mongo_session' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/sessions.rb:157:in collection' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/contextual/mongo.rb:217:in initialize' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/contextual.rb:47:in new' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/contextual.rb:47:in create_context' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/contextual.rb:30:in context' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/contextual.rb:18:in distinct' /app/app/controllers/my_controller.rb:14:in index' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_controller/metal/implicit_render.rb:4:in send_action' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/abstract_controller/base.rb:167:in process_action' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_controller/metal/rendering.rb:10:in process_action' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/abstract_controller/callbacks.rb:18:in block in process_action' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:436:in run_647889395514353966__process_action_2178726499830545563_callbacks' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:405:in __run_callback' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:385:in _run_process_action_callbacks' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:81:in run_callbacks' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/abstract_controller/callbacks.rb:17:inprocess_action' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_controller/metal/rescue.rb:29:in process_action' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_controller/metal/instrumentation.rb:30:in block in process_action' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/notifications.rb:123:in block in instrument' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/notifications/instrumenter.rb:20:in instrument' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/notifications.rb:123:in instrument' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_controller/metal/instrumentation.rb:29:in process_action' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_controller/metal/params_wrapper.rb:205:in process_action' /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.3/lib/active_record/railties/controller_runtime.rb:18:in process_action' /app/vendor/bundle/ruby/1.9.1/gems/newrelic_rpm-3.4.1/lib/new_relic/agent/instrumentation/rails3/action_controller.rb:34:in block in process_action' /app/vendor/bundle/ruby/1.9.1/gems/newrelic_rpm-3.4.1/lib/new_relic/agent/instrumentation/controller_instrumentation.rb:262:in block in perform_action_with_newrelic_trace' /app/vendor/bundle/ruby/1.9.1/gems/newrelic_rpm-3.4.1/lib/new_relic/agent/method_tracer.rb:242:in trace_execution_scoped' /app/vendor/bundle/ruby/1.9.1/gems/newrelic_rpm-3.4.1/lib/new_relic/agent/instrumentation/controller_instrumentation.rb:257:in perform_action_with_newrelic_trace' /app/vendor/bundle/ruby/1.9.1/gems/newrelic_rpm-3.4.1/lib/new_relic/agent/instrumentation/rails3/action_controller.rb:33:in process_action' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/abstract_controller/base.rb:121:in process' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/abstract_controller/rendering.rb:45:in process' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_controller/metal.rb:203:in dispatch' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_controller/metal/rack_delegation.rb:14:in dispatch' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_controller/metal.rb:246:in block in action' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/routing/route_set.rb:73:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/routing/route_set.rb:73:in dispatch' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/routing/route_set.rb:36:in call' /app/vendor/bundle/ruby/1.9.1/gems/journey-1.0.4/lib/journey/router.rb:68:in block in call' /app/vendor/bundle/ruby/1.9.1/gems/journey-1.0.4/lib/journey/router.rb:56:in each' /app/vendor/bundle/ruby/1.9.1/gems/journey-1.0.4/lib/journey/router.rb:56:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/routing/route_set.rb:600:in call' /app/vendor/bundle/ruby/1.9.1/gems/omniauth-1.0.3/lib/omniauth/strategy.rb:168:in call!' /app/vendor/bundle/ruby/1.9.1/gems/omniauth-1.0.3/lib/omniauth/strategy.rb:148:in call' /app/vendor/bundle/ruby/1.9.1/gems/omniauth-1.0.3/lib/omniauth/builder.rb:42:in call' /app/vendor/bundle/ruby/1.9.1/gems/newrelic_rpm-3.4.1/lib/new_relic/rack/browser_monitoring.rb:12:in call' /app/vendor/bundle/ruby/1.9.1/gems/exceptional-2.0.32/lib/exceptional/integration/rack_rails.rb:13:in call' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/rack/mongoid/middleware/identity_map.rb:33:in block in call' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/mongoid/unit_of_work.rb:39:in unit_of_work' /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.4/lib/rack/mongoid/middleware/identity_map.rb:33:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/best_standards_support.rb:17:in call' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/etag.rb:23:in call' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/conditionalget.rb:25:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/head.rb:14:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/params_parser.rb:21:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/flash.rb:242:in call' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/session/abstract/id.rb:205:in context' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/session/abstract/id.rb:200:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/cookies.rb:338:in call' /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.3/lib/active_record/query_cache.rb:64:in call' /app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:467:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/callbacks.rb:28:in block in call' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:405:in run_2458689492548881573_call_1062142932397414625__callbacks' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:405:in __run_callback' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:385:in _run_call_callbacks' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:81:in run_callbacks' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/callbacks.rb:27:in call' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/sendfile.rb:102:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/remote_ip.rb:31:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/debug_exceptions.rb:16:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/show_exceptions.rb:56:in call' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/rack/logger.rb:26:in call_app' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/rack/logger.rb:16:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/request_id.rb:22:in call' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/methodoverride.rb:21:in call' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/runtime.rb:17:in call' /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.3/lib/active_support/cache/strategy/local_cache.rb:72:in call' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/lock.rb:15:in call' /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.3/lib/action_dispatch/middleware/static.rb:62:in call' /app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:136:in forward' /app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:245:in fetch' /app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:185:in lookup' /app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:66:in call!' /app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:51:in call' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/engine.rb:479:in call' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/application.rb:220:in call' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/railtie/configurable.rb:30:in method_missing' /app/vendor/bundle/ruby/1.9.1/gems/newrelic_rpm-3.4.1/lib/new_relic/rack/developer_mode.rb:24:in call' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/content_length.rb:14:in call' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/rack/log_tailer.rb:14:in call' /app/vendor/bundle/ruby/1.9.1/gems/thin-1.4.1/lib/thin/connection.rb:80:in block in pre_process' /app/vendor/bundle/ruby/1.9.1/gems/thin-1.4.1/lib/thin/connection.rb:78:in catch' /app/vendor/bundle/ruby/1.9.1/gems/thin-1.4.1/lib/thin/connection.rb:78:in pre_process' /app/vendor/bundle/ruby/1.9.1/gems/thin-1.4.1/lib/thin/connection.rb:53:in process' /app/vendor/bundle/ruby/1.9.1/gems/thin-1.4.1/lib/thin/connection.rb:38:in receive_data' /app/vendor/bundle/ruby/1.9.1/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in run_machine' /app/vendor/bundle/ruby/1.9.1/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in run' /app/vendor/bundle/ruby/1.9.1/gems/thin-1.4.1/lib/thin/backends/base.rb:63:in start' /app/vendor/bundle/ruby/1.9.1/gems/thin-1.4.1/lib/thin/server.rb:159:in start' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/handler/thin.rb:13:in run' /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:265:in start' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/commands/server.rb:70:in start' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/commands.rb:55:in block in ' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/commands.rb:50:in tap' /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/commands.rb:50:in ' script/rails:6:in require' script/rails:6:in '

Answer 1

Try pushing this to a new heroku app run:

heroku create

and then push. There is an issue when moving an app from one ruby version to another if you had a very specific set of gems installed. Let me know if that works or does not.