Fix Host key verification failed while building an app on Heroku. It usually happens when you have a github repo as dependency in your app.

Host key verification failed.md

Step 1

Delete the package-lock.json file from your project.

Step 2

Clear the build cache

First install the plugin:

heroku plugins:install heroku-builds

Then use the following command to clear the cache:

heroku builds:cache:purge -a example-app

The cache will be rebuilt on the next deploy. If you do not have any new code to deploy, you can push an empty commit.

Worked for me too. Thanks