Heroku run rake db:migrate error rake command not found

I had the same problem,

The cause was that I hadn't specified a remote branch when first pushing to Heroku, Heroku apps start with a blank repository – they have no branches and no code. So the first time you deploy, you need to specify a remote branch.

git push heroku master

I hadn't done this initially and in doing so this fixed my rake problem.

See if the gem sqlite is in development only.

like this

group :development do  gem 'sqlite3'  gem 'web-console'  gem 'listen', '~> 3.0.5'  gem 'spring'  gem 'spring-watcher-listen', '~> 2.0.0'end

To check to see if your app deployed correctly just look at the trace in your shell after you attempt to push to Heroku. I had been running mine in Cloud 9 and not really looking at the results because they were so small, I'm new to this, and, heck, it had always deployed perfectly before....

When I scrolled through I found two errors mentioned; I corrected these errors, then the heroku db migration ran fine. One error was a missing line of code, the other I found on SO (which I can't refind the link to, sorry), and it had to do with the file extensions for my css files, which I changed from .css to .css.scss.