there's a bug in the latest 2.7 version of the container
docker pull python:2.7
docker run -it --rm python:2.7 bash -c 'apt-get update && apt-get install -y supervisor && supervisord —help'
...
...
Processing triggers for systemd (215-17+deb8u4) ...
bash: /usr/bin/supervisord: /usr/bin/python: bad interpreter: No such file or directory