I am currently trying to deploy a dockerized app on Heroku.
It uses a multi-stage build process. The docker image builds fine on my local machine. It also works when the image is pushed using Container Registry. However, the build fails when using a heroku.yml file. It always fails to copy from a previous container.
The code for this looks something like: COPY --from=builder /usr/app/client/build ./build/
I know that the folder exists as running the docker build . command works fine on my local machine. I also know that multistage builds are only supported with Docker 17.x and above. Is this the expected behaviour or am I missing something in the documentation?
