if [[ ${TARGET_OS} ]]; then
    # Target explicitly set
    :
elif [[ $LOCAL_OS == Linux ]]; then
    TARGET_OS=linux
    readlink_flags="-f"
elif [[ $LOCAL_OS == Darwin ]]; then
    TARGET_OS=darwin
    readlink_flags=""
else
    echo "This system's OS, $LOCAL_OS, isn't supported"
    exit 1
fi

# Build image to use
TOOLS_REGISTRY_PROVIDER=${TOOLS_REGISTRY_PROVIDER:-gcr.io}