    # kate: hl earthfile;

    VERSION --shell-out-anywhere 0.6

    # BEGIN Global parameters
    ARG DEVTOOLSET_VERSION = 11
    ARG DEVTOOLSET = devtoolset-${DEVTOOLSET_VERSION}
    # END Global parameters

    ARG param_1 = "String w/ variable interpolation ${DEVTOOLSET}"
    ARG param_2 = 'String w/o variable interpolation ${DEVTOOLSET}'
    # Run shell command
    ARG param_3 = $(echo "String w/ variable interpolation ${DEVTOOLSET}")

    sample-target:
        FROM alpine
        ARG stage
        COPY --if-exists files/${stage}/ /files/
        SAVE ARTIFACT --keep-ts /files /share

    repos-conf-apt:
        ARG image
        ARG ppa

        FROM ${image}

        ENV DEBIAN_FRONTEND=noninteractive
        ENV DEBCONF_NONINTERACTIVE_SEEN=true

        IF [ "${ppa}" != '' ]
            ARG _more_cmds = add-apt-repository -y -n ppa:${ppa}/ppa
        ELSE
            ARG _more_cmds = :
        END

        RUN --mount type=secret,id=+secrets/repo_gpg_key,target=/run/secrets/private-archive-keyring.gpg \
            --mount type=cache,target=/var/cache/apt/archives \
            --mount type=cache,target=/var/lib/apt/lists \
            set -x; \
            debconf-set-selections /tmp/debconf-preset.txt \
         && rm -rf /etc/apt/apt.conf.d/docker-clean \
         && apt-get update \
         && apt-get install -y software-properties-common \
         && add-apt-repository --remove multiverse \
         && gpg -v --dearmor - </run/secrets/private-archive-keyring.gpg > /usr/share/keyrings/private-archive-keyring.gpg \
         && ${_more_cmds}

        SAVE ARTIFACT /etc/apt/sources.list /sources.list
        SAVE ARTIFACT /usr/share/keyrings/private-archive-keyring.gpg /private-archive-keyring.gpg

        IF [ "${ppa}" != '' ]
            SAVE ARTIFACT /etc/apt/sources.list.d/${ppa}*.list /sources.list.d
            SAVE ARTIFACT /etc/apt/trusted.gpg.d/${ppa}*.gpg /trusted.gpg.d
        END

    APT_INSTALL:
        FUNCTION

        ARG image
        ARG packages = ''
        ARG packages_on_hold = ''
        ARG upgrade = 0
        ARG clean = 0
        ARG pm_aux_options = ''
        ARG more_rm_files = ''
        ARG more_cmds = :

        IF [ ! -f /root/debconf-preset.txt ]
            COPY (+repos-conf-apt/debconf-preset.txt --image=${image}) /root/debconf-preset.txt
            ARG _debconf_cmd_cond = debconf-set-selections /root/debconf-preset.txt
        ELSE
            ARG _debconf_cmd_cond = :
        END

        IF [ ! -f /usr/share/keyrings/private-archive-keyring.gpg ]
            COPY (+repos-conf-apt/private-archive-keyring.gpg --image=${image}) \
                /usr/share/keyrings/private-archive-keyring.gpg
            # NOTE Also copy the `sources.list` file with `multiverse` disabled!
            COPY (+repos-conf-apt/sources.list --image=${image}) /etc/apt
        END

        # ...

    MAKE_PYTHON_CI_IMAGE:
        FUNCTION

        ARG image
        ARG python = python3
        ARG python_pkg = ${python}
        ARG python_bin = ${python}
        ARG python_ver = 3.11

        DO +APT_INSTALL --packages="${python_pkg} git"

        ARG _chroot_base = $(dirname $(cat /etc/debian_chroot))

        DO ./share+IMAGE_INIT \
            --image_description="CI image for Python projects" \
            --debian_chroot=${_chroot_base}/python/${python_ver}/ci \
            --storage_name=none

        COPY --dir (+prep-python-ci/local --image=${image}) /usr

        ENV SETUPTOOLS_USE_DISTUTILS='stdlib'
        ENV PIP_DISABLE_PIP_VERSION_CHECK=1

    all:
        LOCALLY

        # Primary images
        BUILD +ci
        BUILD +clang-ci
        BUILD +python-ci

        IF [ "${BUILD_TESTING}" -gt 0 ]
            # Also include all tests
            BUILD +tests
        END

    tests:
        LOCALLY

        BUILD +ci-tests
        BUILD +clang-ci-tests
        BUILD +python-ci-tests

    ci-tests:
        FROM +ci
        COPY .env /
        DO share+RUN_TESTS --VERBOSE=${VERBOSE}

    clang-ci-tests:
        FROM +clang-ci
        COPY .env /
        ENV EXPECT_CLANG_VERSION=${CLANG_VERSION}
        DO share+RUN_TESTS --VERBOSE=${VERBOSE} --script=ci-tests.sh

    python-ci-tests:
        FROM +python-ci
        COPY .env /
        DO share+RUN_TESTS --VERBOSE=${VERBOSE}