Why does my app "fail to detect" a buildpack?

Resolution

This error message means that Heroku was unable to automatically detect the type of app you're trying to deploy: Ruby, Node, Python, PHP, Java, etc. We look for signatures for each language we support (like a pom.xml file or package.json file).

Most apps have at least one of these signatures present, so if you see this error, it usually means an important file isn't checked into your git repository:

  • Java: pom.xml
  • Ruby: Gemfile
  • Node.js: package.json
  • Python: requirements.txt / setup.py / Pipfile
  • PHP: composer.json / index.php

You should git add {file}, git commit -am 'added {file}' and then git push heroku master.