dockerfile issues, solutions in here: disable buildkit and run last command in own line

[Liquidmasl]

I was struggling getting the dockerfile to run.

here are the steps to make it work:

As you know, nvidia runtime needs to be available at buildtime.
ADDITIONALLY: because of a regression on dockers part buildkit needs to be disabled via env variable before running docker build

DOCKER_BUILDKIT=0

Additionally, for some reason the row

RUN cd decord && mkdir build && cd build && cmake .. -DUSE_CUDA=ON -DCMAKE_BUILD_TYPE=Release && make -j2 && cd ../python && python3 setup.py install

fails because it cant find numpy (i think)

just changing that to

RUN cd decord && mkdir build && cd build && cmake .. -DUSE_CUDA=ON -DCMAKE_BUILD_TYPE=Release && make -j2
   
RUN pip install numpy

WORKDIR /decord/python
RUN python3 setup.py install

fixed that and makes the docker build not fail.