Heroku Deploy Error: No Default Language - ruby-on-rails

Question

I am trying to push some ruby code with git and keep getting stopped part way through. Here is my setup and error I get..
root#slacker:~/ruby# git remote -v
heroku https://git.heroku.com/warm-woodland-27175.git (fetch)
heroku https://git.heroku.com/warm-woodland-27175.git (push)
root#slacker:~/ruby# ls
config.ru myapp.rb
root#slacker:~/ruby# git push heroku master
Counting objects: 4, done.
Compressing objects: 100% (3/3), done.
Writing objects: 100% (4/4), 398 bytes | 0 bytes/s, done.
Total 4 (delta 0), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote:
remote: ! No default language could be detected for this app.
remote: HINT: This occurs when Heroku cannot detect the buildpack to use for this application automatically.
remote: See https://devcenter.heroku.com/articles/buildpacks
remote:
remote: ! Push failed
remote: Verifying deploy...
remote:
remote: ! Push rejected to warm-woodland-27175.
remote:
To https://git.heroku.com/warm-woodland-27175.git
! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/warm-woodland- 27175.git'
root#slacker:~/ruby#
I am still trying to understand the ins and outs of git but I am pretty lost as to why git doesn't recognize the file extensions in my compilation folder. I thought that was how it fetched what language to use, .rb .pl etc... Any help would be much appreciated.

Answer 1

I had this error when trying to deploy my Sinatra app to Heroku.
heroku buildpacks:set heroku/ruby
I read https://devcenter.heroku.com/articles/buildpacks which helped me finish the solution.
But I started with https://devcenter.heroku.com/articles/rack
which helped me understand the files that you need to add such as the Gemfile etc. Make sure you do the bundle install.
Make sure you committed your changes after you added the Gemfile, etc. So
git add .
or whatever you need to do it then commit
git commit -m "Added files for Heroku deployment"
or change the message as you want. and then can you deploy using
git push heroku master
Now I have my site running using heroku
If I am missing something that you need, just ask in comments so I can clarify.

Answer 2

I had the same issue when I was trying to deploy to Heroku with Ruby Sinatra. The issue in my case was that I'm brand new to Ruby and Sinatra and didn't know anything about the gems and bundling.
I literally only had my app.rb file in the folder.
I took the following steps, based on some guides 1 I read:
If my app is called app.rb, create a file called config.ru:
require './hello'
run Sinatra::Application
Create a file called Gemfile:
source 'https://rubygems.org'
gem 'sinatra'
Then I found this article that reminded me that I need to run bundle install.
Then I add these files to my git, pushed it, and mine is working!