opengl docker image build error

[tatsuya-ishihara]

Because of the recent update of Nvidia Ubuntu 20.04 docker image, "cabot/docker/prebuild-docker.sh" fails to build the image "nvidia-cuda11.1-cudnn8-devel-glvnd-runtime-ubuntu20.04". The error is same to here.

This error is caused because the latest "libc6:i386" package for Ubuntu20.04 cannot be installed without "-o APT::Immediate-Configure=0" option. Temporal solution to solve this build error is modifying "cabot/docker/prebuild/opengl/base/Dockerfile" as follows.

 RUN dpkg --add-architecture i386 && \
     apt-get update && apt-get install -y --no-install-recommends \
+       -o APT::Immediate-Configure=0 \
         libxau6 libxau6:i386 \
         libxdmcp6 libxdmcp6:i386 \
         libxcb1 libxcb1:i386 \

Currently this is necessary to build docker image, but it may be solved by the update of Nvidia docker image.

[daisukes]

#10