anchor.diff:      && useradd -u ${uid} -g ${gid} -m -s /bin/bash ${user} \
       && echo "${user} ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/90-passwordless-sudo
   
  +COPY . /home/${user}
  +RUN chown -R ${user}:${user} /home/${user}
  +
   # drop root
   USER ${user}
  +WORKDIR /home/${user}
  
positive.code:     && apt-get install -y crossbuild-essential-armhf crossbuild-essential-arm64
  
  # mclient build dependencies
  # multiarch libs are done in a separate apt-get command to avoid weird conflicts
  # NOTE: libxi-dev is broken and always removes the previous installed architecture...
  RUN apt-get install -y \
      libx11-dev \
      libxfixes-dev \
      libxext-dev \
      libxdamage-dev \
      libxi-dev \
      libxrandr-dev \
  && apt-get install -y \
      libx11-dev:armhf \
      libxfixes-dev:armhf \
      libxext-dev:armhf \
  
negative.code:     libxext-dev:arm64 \
      libxdamage-dev:arm64 \
      libxi-dev:arm64 \
      libxrandr-dev:arm64 \
  && apt-get install -y \
      libx11-dev \
      libxfixes-dev \
      libxext-dev \
      libxdamage-dev \
      libxi-dev \
      libxrandr-dev
  
  RUN apt-get clean && rm -rf /var/lib/apt/lists/*
  
  # create a non-root user
  ARG user=dev
  