anchor.diff:      && 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...
  +# thus, multiarch libs are done in a separate apt-get command to avoid weird conflicts
   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 \
  
positive.code:     && useradd -u ${uid} -g ${gid} -m -s /bin/bash ${user} \
      && echo "${user} ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/90-passwordless-sudo
  
  # drop root
  USER ${user}
  
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
  