Cannot cache Github action with docker compose - github

Question

I'm trying to create a cache for the following Github action:
name: dockercompose
on: push
jobs:
test:
runs-on: ubuntu-18.04
steps:
- uses: actions/checkout#v1
- name: Cache Docker Compose
id: cache-docker
uses: actions/cache#v1
with:
path: fhe_app/
key: cache-docker
- name: Build the stack
run: docker-compose up -d
working-directory: fhe_app/
whit the following Dockerfile:
FROM tensorflow/tensorflow:nightly-py3
# set work directory
WORKDIR /usr/src/app
# set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
# install dependencies
RUN python3 -m pip install --upgrade pip
COPY local_requirements.txt /usr/src/app/local_requirements.txt
RUN \
apt-get update && \
apt-get -y install python3 postgresql-server-dev-10 gcc python3-dev musl-dev netcat
RUN python3 -m pip install -r local_requirements.txt
# copy entrypoint.sh
COPY entrypoint.sh /usr/src/app/entrypoint.sh
RUN chmod +x entrypoint.sh
# copy project
COPY . /usr/src/app/
# run entrypoint.sh
ENTRYPOINT ["/usr/src/app/entrypoint.sh"]
When pushing to Github, instead of a success message, I get:
Cache Docker Compose
Cache not found for input keys: cache-docker.
And:
Post Cache Docker Compose
Post job cleanup.
/bin/tar -cz -f /home/runner/work/_temp/e13e2694-e020-476d-888e-cb29cb9184b6/cache.tgz -C /home/runner/work/fhe_server/fhe_server/fhe_app .
/bin/tar: ./app: file changed as we read it
##[warning]The process '/bin/tar' failed with exit code 1
I've other yml files not using Docker that are caching properly, so the overall structure of the yml should be fine. Is this the right way to cache docker-compose?