Ruby on Rails, error when pushing to Heroku - database issue?

Question

I am new to Ruby on Rails, and new to programming in general, so I'm having trouble reading this log and understanding the issue. I just created a simple app in Rails and I'm trying to push it to Heroku. I understand that there is an issue with sqlite and Heroku, so I changed my gem file to:

 source 'https://rubygems.org'


    gem 'rails', '4.0.2'
    gem 'sass-rails', '~> 4.0.0'
    gem 'uglifier', '>= 1.3.0'
    gem 'coffee-rails', '~> 4.0.0'
    gem 'jquery-rails'
    gem 'turbolinks'
    gem 'jbuilder', '~> 1.2'
    gem 'bootstrap-sass'

    group :development, :test do
    gem 'sqlite3'
    end

    group :production do
    gem 'pg'
    gem 'rails_12factor'
    end

group :doc do  
gem 'sdoc', require: false
end

And then I ran bundle install -- without production. Then I pushed it to git and heroku through the command line. It seemed to work, but when I go to the page heroku created I get this message: Application Error An error occurred in the application and your page could not be served. Please try again in a few moments.

If you are the application owner, check your logs for details.

So then I ran heroku logs --tail and got this message.

I can't figure out what's causing the problem. I'm only about two days into working with programming or Rails so this is confusing. Thank you.

    $ git push heroku master
Warning: Permanently added the RSA host key for IP address '50.19.85.154' to the
 list of known hosts.
Enter passphrase for key '/c/Users/Lisa/.ssh/id_rsa':
Fetching repository, done.
To git@heroku.com:tranquil-earth-2932.git
 ! [rejected]        master -> master (non-fast-forward)
error: failed to push some refs to 'git@heroku.com:tranquil-earth-2932.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Integrate the remote changes (e.g.
hint: 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

Lisa@LISA-HP /c/users/lisa/desktop/pinteresting (master)
$ heroku logs --tail
←[36m2014-05-20T22:11:18.020685+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:76:in `require'
←[36m2014-05-20T22:11:18.020763+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:72:in `block in require'
←[36m2014-05-20T22:11:18.020724+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:76:in `block (2 levels) in
require'
←[36m2014-05-20T22:11:18.020782+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:61:in `each'
←[36m2014-05-20T22:11:18.020801+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:61:in `require'
←[36m2014-05-20T22:11:18.020528+00:00 app[web.1]:←[0m /app/vendor/bundle/ruby/2.
0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:33:in `require': canno
t load such file -- less-rails (LoadError)
←[36m2014-05-20T22:11:18.020578+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:33:in `register
_rails_engine'
←[36m2014-05-20T22:11:18.020953+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `<top (required)>'
←[36m2014-05-20T22:11:18.020608+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:6:in `load!'
←[36m2014-05-20T22:11:18.020840+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler.rb:131:in `require'
←[36m2014-05-20T22:11:18.020859+00:00 app[web.1]:←[0m   from /app/config/applica
tion.rb:7:in `<top (required)>'
←[36m2014-05-20T22:11:18.020897+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `block in <top (requi
red)>'
←[36m2014-05-20T22:11:18.020916+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `tap'
←[36m2014-05-20T22:11:18.020878+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `require'
←[36m2014-05-20T22:11:18.020991+00:00 app[web.1]:←[0m   from bin/rails:4:in `<ma
in>'
←[36m2014-05-20T22:11:18.020973+00:00 app[web.1]:←[0m   from bin/rails:4:in `req
uire'
←[33m2014-05-20T22:11:21.182626+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/ host=tranquil-earth-2932.herokuapp.com request_
id=6b22fce3-ca34-4403-85a4-3ad841ee2d72 fwd="50.143.161.142" dyno= connect= serv
ice= status=503 bytes=
←[33m2014-05-20T22:11:21.409050+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/favicon.ico host=tranquil-earth-2932.herokuapp.c
om request_id=eb61a469-11e0-47b9-bec6-7045bb9e1c1b fwd="50.143.161.142" dyno= co
nnect= service= status=503 bytes=
←[36m2014-05-20T22:11:19.742708+00:00 heroku[web.1]:←[0m State changed from star
ting to crashed
←[36m2014-05-20T22:11:19.735501+00:00 heroku[web.1]:←[0m Process exited with sta
tus 1
←[33m2014-05-20T22:12:40.925333+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/ host=tranquil-earth-2932.herokuapp.com request_
id=cdff1d04-0fb5-471a-b88f-3cc3b450fe27 fwd="50.143.161.142" dyno= connect= serv
ice= status=503 bytes=
←[33m2014-05-20T22:12:41.137018+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/favicon.ico host=tranquil-earth-2932.herokuapp.c
om request_id=15cceead-cbd0-4b89-8111-3e0750e490f5 fwd="50.143.161.142" dyno= co
nnect= service= status=503 bytes=
←[33m2014-05-20T22:41:31.750337+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/ host=tranquil-earth-2932.herokuapp.com request_
id=1bc63ffa-116d-4071-90c2-dfdb232939f4 fwd="50.143.161.142" dyno= connect= serv
ice= status=503 bytes=
←[36m2014-05-20T22:54:59.342657+00:00 heroku[web.1]:←[0m State changed from cras
hed to starting
←[36m2014-05-20T22:55:06.506950+00:00 app[web.1]:←[0m /app/vendor/bundle/ruby/2.
0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:33:in `require': canno
t load such file -- less-rails (LoadError)
←[36m2014-05-20T22:55:06.507015+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:6:in `load!'
←[36m2014-05-20T22:55:06.506994+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:33:in `register
_rails_engine'
←[36m2014-05-20T22:55:06.507035+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:41:in `<top (re
quired)>'
←[36m2014-05-20T22:55:06.507056+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font-awesome-less.rb:1:in `require'
←[36m2014-05-20T22:55:06.507097+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font-awesome-less.rb:1:in `<top (req
uired)>'
←[36m2014-05-20T22:55:06.507117+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:76:in `require'
←[36m2014-05-20T22:55:06.507137+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:76:in `block (2 levels) in
require'
←[36m2014-05-20T22:55:06.507157+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:72:in `each'
←[36m2014-05-20T22:55:06.507177+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:72:in `block in require'
←[36m2014-05-20T22:55:06.507211+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:61:in `each'
←[36m2014-05-20T22:55:06.507249+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler.rb:131:in `require'
←[36m2014-05-20T22:55:06.507231+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:61:in `require'
←[36m2014-05-20T22:55:06.507268+00:00 app[web.1]:←[0m   from /app/config/applica
tion.rb:7:in `<top (required)>'
←[36m2014-05-20T22:55:06.507286+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `require'
←[36m2014-05-20T22:55:06.507322+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `block in <top (requi
red)>'
←[36m2014-05-20T22:55:06.507341+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `tap'
←[36m2014-05-20T22:55:06.507359+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `<top (required)>'
←[36m2014-05-20T22:55:06.507378+00:00 app[web.1]:←[0m   from bin/rails:4:in `req
uire'
←[36m2014-05-20T22:55:06.507396+00:00 app[web.1]:←[0m   from bin/rails:4:in `<ma
in>'
←[36m2014-05-20T22:55:07.928729+00:00 heroku[web.1]:←[0m State changed from star
ting to crashed
←[36m2014-05-20T22:55:03.863011+00:00 heroku[web.1]:←[0m Starting process with c
ommand `bin/rails server -p 13720 -e production`
←[36m2014-05-20T22:55:07.816698+00:00 heroku[web.1]:←[0m Process exited with sta
tus 1
←[33m2014-05-20T23:06:39.203070+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/ host=tranquil-earth-2932.herokuapp.com request_
id=28c91df1-e7e8-4e69-9657-08c4a37b428c fwd="50.143.161.142" dyno= connect= serv
ice= status=503 bytes=
←[33m2014-05-20T23:06:39.348326+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/favicon.ico host=tranquil-earth-2932.herokuapp.c
om request_id=53206354-ff5c-4f71-86e1-035adf6f2221 fwd="50.143.161.142" dyno= co
nnect= service= status=503 bytes=
←[33m2014-05-20T23:06:43.830039+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/ host=tranquil-earth-2932.herokuapp.com request_
id=de4cf78f-6912-480f-82f7-87c6c6fd66a6 fwd="50.143.161.142" dyno= connect= serv
ice= status=503 bytes=
←[33m2014-05-20T23:06:44.000423+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/favicon.ico host=tranquil-earth-2932.herokuapp.c
om request_id=d9b27929-a7cf-412f-a749-1ea8e75ea8c3 fwd="50.143.161.142" dyno= co
nnect= service= status=503 bytes=
←[36m2014-05-20T23:40:11.750892+00:00 heroku[web.1]:←[0m State changed from cras
hed to starting
←[36m2014-05-20T23:40:16.537318+00:00 app[web.1]:←[0m /app/vendor/bundle/ruby/2.
0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:33:in `require': canno
t load such file -- less-rails (LoadError)
←[36m2014-05-20T23:40:16.537362+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:61:in `each'
←[36m2014-05-20T23:40:16.537340+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:33:in `register
_rails_engine'
←[36m2014-05-20T23:40:16.537365+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:61:in `require'
←[36m2014-05-20T23:40:16.537343+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:6:in `load!'
←[36m2014-05-20T23:40:16.537369+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler.rb:131:in `require'
←[36m2014-05-20T23:40:16.537345+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:41:in `<top (re
quired)>'
←[36m2014-05-20T23:40:16.537372+00:00 app[web.1]:←[0m   from /app/config/applica
tion.rb:7:in `<top (required)>'
←[36m2014-05-20T23:40:16.537346+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font-awesome-less.rb:1:in `require'
←[36m2014-05-20T23:40:16.537410+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `require'
←[36m2014-05-20T23:40:16.537348+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font-awesome-less.rb:1:in `<top (req
uired)>'
←[36m2014-05-20T23:40:16.537415+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `block in <top (requi
red)>'
←[36m2014-05-20T23:40:16.537351+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:76:in `require'
←[36m2014-05-20T23:40:16.537417+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `tap'
←[36m2014-05-20T23:40:16.537353+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:76:in `block (2 levels) in
require'
←[36m2014-05-20T23:40:16.537420+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `<top (required)>'
←[36m2014-05-20T23:40:16.537426+00:00 app[web.1]:←[0m   from bin/rails:4:in `<ma
in>'
←[36m2014-05-20T23:40:16.537355+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:72:in `each'
←[36m2014-05-20T23:40:16.537423+00:00 app[web.1]:←[0m   from bin/rails:4:in `req
uire'
←[36m2014-05-20T23:40:16.537358+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:72:in `block in require'
←[36m2014-05-20T23:40:17.653829+00:00 heroku[web.1]:←[0m State changed from star
ting to crashed
←[36m2014-05-20T23:40:14.432603+00:00 heroku[web.1]:←[0m Starting process with c
ommand `bin/rails server -p 30369 -e production`
←[36m2014-05-20T23:40:17.640831+00:00 heroku[web.1]:←[0m Process exited with sta
tus 1
←[36m2014-05-21T01:02:44.418153+00:00 heroku[web.1]:←[0m State changed from cras
hed to starting
←[36m2014-05-21T01:02:51.071476+00:00 app[web.1]:←[0m /app/vendor/bundle/ruby/2.
0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:33:in `require': canno
t load such file -- less-rails (LoadError)
←[36m2014-05-21T01:02:51.071501+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:6:in `load!'
←[36m2014-05-21T01:02:51.071499+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:33:in `register
_rails_engine'
←[36m2014-05-21T01:02:51.071504+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font-awesome-less.rb:1:in `require'
←[36m2014-05-21T01:02:51.071503+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:41:in `<top (re
quired)>'
←[36m2014-05-21T01:02:51.071506+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/font-awesome-less-4.1.0/lib/font-awesome-less.rb:1:in `<top (req
uired)>'
←[36m2014-05-21T01:02:51.071508+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:76:in `require'
←[36m2014-05-21T01:02:51.071513+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:72:in `each'
←[36m2014-05-21T01:02:51.071518+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:61:in `require'
←[36m2014-05-21T01:02:51.071519+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler.rb:131:in `require'
←[36m2014-05-21T01:02:51.071509+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:76:in `block (2 levels) in
require'
←[36m2014-05-21T01:02:51.071516+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:61:in `each'
←[36m2014-05-21T01:02:51.071515+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/bundler-1.5.2/lib/bundler/runtime.rb:72:in `block in require'
←[36m2014-05-21T01:02:51.071521+00:00 app[web.1]:←[0m   from /app/config/applica
tion.rb:7:in `<top (required)>'
←[36m2014-05-21T01:02:51.071528+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `tap'
←[36m2014-05-21T01:02:51.071525+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `require'
←[36m2014-05-21T01:02:51.071526+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `block in <top (requi
red)>'
←[36m2014-05-21T01:02:51.071529+00:00 app[web.1]:←[0m   from /app/vendor/bundle/
ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `<top (required)>'
←[36m2014-05-21T01:02:51.071531+00:00 app[web.1]:←[0m   from bin/rails:4:in `req
uire'
←[36m2014-05-21T01:02:51.071534+00:00 app[web.1]:←[0m   from bin/rails:4:in `<ma
in>'
←[36m2014-05-21T01:02:52.463039+00:00 heroku[web.1]:←[0m State changed from star
ting to crashed
←[36m2014-05-21T01:02:48.872619+00:00 heroku[web.1]:←[0m Starting process with c
ommand `bin/rails server -p 5886 -e production`
←[36m2014-05-21T01:02:52.444507+00:00 heroku[web.1]:←[0m Process exited with sta
tus 1
←[33m2014-05-21T01:32:39.536275+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/ host=tranquil-earth-2932.herokuapp.com request_
id=8dba47fb-5f6d-4cc4-8c99-cf0733f69306 fwd="50.143.161.142" dyno= connect= serv
ice= status=503 bytes=
←[33m2014-05-21T01:32:39.743826+00:00 heroku[router]:←[0m at=error code=H10 desc
="App crashed" method=GET path=/favicon.ico host=tranquil-earth-2932.herokuapp.c
om request_id=2b9f8656-9258-49cf-b376-ef6b076d58b8 fwd="50.143.161.142" dyno= co
nnect= service= status=503 bytes=

Answer 1

This line appears suspicious:

/app/vendor/bundle/ruby/2.
0.0/gems/font-awesome-less-4.1.0/lib/font_awesome/less.rb:33:in `require': canno
t load such file -- less-rails (LoadError)

font-awesome-less doesn't appear to be in your gemfile, you should probably add it as a dependency.

gem 'font-awesome-less'

See this for usage details.

As an aside, less and sass are more or less equivalent, I would probably pick one and stick with it (font-awesome-less depends on less while you already have sass-rails in your gemfile). font-awesome-rails is the sass equivalent of font-awesome-less.

Answer 2

Further to the wonderful answer posted by hjing , this is the main error preventing you from pushing to Heroku :

error: failed to push some refs to 'git@heroku.com:tranquil-earth-2932.git' hint: Updates were rejected because the tip of your current branch is behind hint: its remote counterpart. Integrate the remote changes (eg hint: 'git pull ...') before pushing again.

The error basically says your remote git repo is ahead of the local. To fix this, as mentioned in the comments, I would:

$ git add .
$ git commit -a -m "Heroku"
$ git pull heroku master # -> this will just merge any of the "ahead" files
$ git add .
$ git commit -a -m "Heroku"
$ git push heroku master

--

SASS

Then you've got your SASS error to deal with

To fix this you need to be able to rectify the issue with the font-awesome-less gem. The answer below should help you with that