Trouble with Deployment of a Rails App to Heroku - ruby

Question

More specifically, I am getting an H10 error when pulling up heroku logs, “No such file to load — pry (LoadError)” when running the rails console on Heroku.
The Rails app runs fine on localhost. I've scoured all of my application's files to remove references to "require 'pry'", and any calls to "binding.pry". The pry-rails and pry-nav gems should not be running in production on Heroku. I've rerun bundle install, reset my databases both locally and on Heroku, ensured my code was pushed up after these adjustments, and have reset the dynos on Heroku.
What gives?
heroku logs
2016-05-02T21:45:04.892586+00:00 heroku[router]: at=error code=H10
desc="App crashed" method=GET path="/" host=chess-workout-andrew-smith.herokuapp.com request_id=f05db461-e4ef-48e4-b920-6b5163fa0ea2 fwd="69.156.77.15" dyno= connect= service= status=503 bytes=
2016-05-02T21:45:05.175027+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=chess-workout-andrew-smith.herokuapp.com request_id=fdbd387c-63fa-49e7-8d2c-e94f36558356 fwd="69.156.77.15" dyno= connect= service= status=503 bytes=
heroku run rails c
/app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/values/time_zone.rb:282: warning: circular argument reference - now
/app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `require': No such file to load -- pry (LoadError)
/app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/values/time_zone.rb:282: warning: circular argument reference - now
/app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `require': No such file to load -- pry (LoadError)
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `block in require'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:214:in `load_dependency'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `require'
from /app/app/controllers/pieces_controller.rb:1:in `<top (required)>'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `require'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `block in require'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:214:in `load_dependency'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `require'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:330:in `require_or_load'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:289:in `depend_on'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:207:in `require_dependency'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/engine.rb:465:in `block (2 levels) in eager_load!'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/engine.rb:464:in `each'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/engine.rb:464:in `block in eager_load!'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/engine.rb:462:in `each'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/engine.rb:462:in `eager_load!'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/engine.rb:347:in `eager_load!'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/application/finisher.rb:56:in `each'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/application/finisher.rb:56:in `block in <module:Finisher>'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/initializable.rb:30:in `instance_exec'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/initializable.rb:30:in `run'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/initializable.rb:55:in `block in run_initializers'
from /app/vendor/ruby-2.2.4/lib/ruby/2.2.0/tsort.rb:226:in `block in tsort_each'
from /app/vendor/ruby-2.2.4/lib/ruby/2.2.0/tsort.rb:348:in `block (2 levels) in each_strongly_connected_component'
from /app/vendor/ruby-2.2.4/lib/ruby/2.2.0/tsort.rb:429:in `each_strongly_connected_component_from'
from /app/vendor/ruby-2.2.4/lib/ruby/2.2.0/tsort.rb:347:in `block in each_strongly_connected_component'
from /app/vendor/ruby-2.2.4/lib/ruby/2.2.0/tsort.rb:345:in `each'
from /app/vendor/ruby-2.2.4/lib/ruby/2.2.0/tsort.rb:345:in `call'
from /app/vendor/ruby-2.2.4/lib/ruby/2.2.0/tsort.rb:345:in `each_strongly_connected_component'
from /app/vendor/ruby-2.2.4/lib/ruby/2.2.0/tsort.rb:224:in `tsort_each'
from /app/vendor/ruby-2.2.4/lib/ruby/2.2.0/tsort.rb:203:in `tsort_each'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/initializable.rb:54:in `run_initializers'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/application.rb:215:in `initialize!'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /app/config/environment.rb:5:in `<top (required)>'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `require'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `block in require'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:214:in `load_dependency'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `require'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/application.rb:189:in `require_environment!'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.0.1/lib/rails/commands.rb:61:in `<top (required)>'
from /app/bin/rails:4:in `require'
from /app/bin/rails:4:in `<main>'
Gemfile:
source 'https://rubygems.org'
gem 'simple_form'
gem 'rails', '4.0.1'
gem 'pg'
gem 'sass-rails', '~> 4.0.0'
gem 'uglifier', '>= 1.3.0'
gem 'coffee-rails', '~> 4.0.0'
gem 'rails_12factor', group: :production
gem 'jquery-rails'
gem 'turbolinks'
gem 'jbuilder', '~> 1.2'
gem 'pry-rails', :group => :development
gem 'pry-nav', :group => :development
gem 'awesome_print', :group => :development
group :development, :test do
gem 'rspec-rails', '~> 3.0'
end
group :doc do
gem 'sdoc', require: false
end
gem 'bootstrap-sass', '~> 3.3.4.1'
gem 'sprockets', '<= 2.11.0'
gem "devise"
gem "factory_girl_rails", "~> 4.0"
database.yml
development:
adapter: postgresql
encoding: unicode
database: chess_workout_development
pool: 5
username: postgres
password: password
host: localhost
test:
adapter: postgresql
encoding: unicode
database: chess_workout_test
pool: 5
username: postgres
password: password
host: localhost
production:
adapter: postgresql
encoding: unicode
database: chess_workout_production
pool: 5
username: postgres
password: password
host: localhost

Answer 1

The error log from heroku run rails console said that there is no pry. In Gemfile, pry was only for develop environment even though I am pretty sure that require 'pry' was set in controller file so that heroku is confused.
You can remove pry from :group => :development in Gemfile, and do not forget to heroku run bundle install.