Git pushing to heroku rejected (non-fast-forward updates)

Question

I tried going back to a previous commit on git. Now I'm trying to push it back to heroku.

git push staging-heroku staging:master

To git@heroku.com:MyApp.git
 ! [rejected]        staging -> master (non-fast-forward)
error: failed to push some refs to 'git@heroku.com:MyApp.git'
To prevent you from losing history, non-fast-forward updates were rejected
Merge the remote changes (e.g. 'git pull') before pushing again.  See the
'Note about fast-forwards' section of 'git push --help' for details.

I searched Stackoverflow and they're saying

git push -f git@heroku.com:<heroku repo name>.git

I tried that and I get

Total 0 (delta 0), reused 0 (delta 0)


 !     Push rejected, no Cedar-supported app detected

To git@heroku.com:MyApp.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'git@MyApp.git'

Update

Winfield's suggesting checking my Procfile

cat Procfile

web: node app.js

git add Procfile and git push -f git@heroku.com:MyApp.git gives me the same error message.

Answer 1

The current error you're seeing is the Heroku Ruby buildpack failing to identify and integrate with a Ruby application from your git repo.

This means you are missing one or more of the following:

• Gemfile with gem depdencies and ruby version
• Procfile with one or more ruby processes to run