Exports the Heroku SOURCE_VERSION variable (usually the Git SHA) to an env variable that application code can access.
The first step is to add the Heroku multi buildpack to your app.
Next, create a .buildpacks file in your app repo or edit an existing file. Add this to the file:
https://github.com/cahootify/heroku-buildpack-git-sha.git
The Git sha will now be available to application code via the env var GIT_SHA.
MIT