Why is my Heroku push rejected? - ruby-on-rails

Question

I am working through chapter 1 of Hartl's Rails 4.0 tutorial, and I'm stuck on Section 1.4.2, which is to push a black app into GitHub and Heroku.
I tried typing git push heroku master, but I get an error message, similar to a previous question on StackOverFlow:
Heroku push rejected - Hartl's Rails 3.2 tutorial
Heroku push rejected, railties dependency conflict? Ruby on Rails Tutorial Section 1.4.2
It's probably the same but I don't even realize it:
-----> Ruby/Rails app detected
-----> Installing dependencies using
Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin --deployment
/usr/bin/env: ruby1.9.1: No such file or directory
!
! Failed to install gems via Bundler.
!
! Heroku push rejected, failed to compile Ruby/Rails app
Here is the Gemfile I used:
source 'https://rubygems.org'
ruby '1.9.3'
gem 'rails', '4.0.0.rc1'
group :development do
gem 'sqlite3', '1.3.7'
end
gem 'sass-rails', '4.0.0.rc1'
gem 'uglifier', '2.1.1'
gem 'coffee-rails', '4.0.0'
gem 'jquery-rails', '2.2.1'
gem 'turbolinks', '1.1.1'
gem 'jbuilder', '1.0.2'
group :doc do
gem 'sdoc', '0.3.20', require: false
end
group :production do
gem 'pg', '0.15.1'
end
UPDATE: The main error seems to be /usr/bin/env: ruby1.9.1: No such file or directory Is that folder on the Heroku machine or my home computer ?
I tried removing the line ruby '1.9.3' from my .gitignore but it still returns this message.

Answer 1

First, Remove ruby 1.9.3 from the Gemfile. You don't need it and may be the cause of your problem. Start of your Gemfile should look like this:
source 'https://rubygems.org'
gem 'rails', '4.0.0.rc1'
group :development do
gem 'sqlite3', '1.3.7'
end
etc........
Also, make sure you run
bundle install --without production
since you are using sqlite3 in :development and postgresql in :production

Answer 2

I had a similar problem. The issue is that Bundler is generating stubs. Rails 4 apps do not store stubs in the app's bin/ directory. In order to fix this problem you need to use the following commands:
$ bundle config --delete bin
Then you need to update the bin directory to use the new Rails 4 executables
$ rake rails:update:bin
Then add the new bin/ directory to your version control using:
$ git add bin
Commit the changes and push your code to Heroku

Answer 3

i had the same problem and the problem was that i didn't chose the version of ruby that i want to use, so i did the following:
$rvm list
ruby-1.9.3-p392 [ i686 ]
ruby-2.0.0-p247 [ i686 ]
$rvm use ruby-1.9.3-p392
$rvm list
=> ruby-1.9.3-p392 [ i686 ]
ruby-2.0.0-p247 [ i686 ]