I was using a container for a bioinformatics tool released two weeks ago, but my shell script wrapping the tools could not run because the container was built around an old version of Debian (Jessie) that was released in 2015. I was asked to use a container for bioinformatics, based on conda, and found one that distributes coreutils, but it did not include a real version of sed. I try Debian's docker image. No luck; it does not contain ps, which my workflow manager needs. But fortunately I eventually figured out that Ubuntu's Docker image contains coreutils, sed and ps together! In the world of containers, this sounds like a little miracle.