We wanted to use the latest version of the image of your black. But that image is running 19.3b0 which is not the latest version when u install black locally.

When trying to build our own version we encountered a problem with the installation. You first need to add:

RUN apk add --no-cache --update gcc build-base

So the Dockerfile would look like this:

FROM python:3-alpine

LABEL io.whalebrew.name 'black'
LABEL io.whalebrew.config.working_dir '/workdir'
WORKDIR /workdir

RUN apk add --no-cache --update gcc build-base
RUN pip install --upgrade black

ENTRYPOINT ["black"]
CMD ["--help"]

After building this you have the newest version of black at your disposal 👍