DevStack has evolved to support a large number of configuration options and alternative platforms and support services. DevStack is an opinionated script to quickly create an OpenStack development environment. It can also be used to demonstrate starting/running OpenStack services and provide examples of using them from a command line.
DevStack's mission is to provide and maintain tools used for the installation of the central OpenStack services from source (git repository master, or specific branches) suitable for development and operational testing. It also demonstrates and documents examples of configuring and running services as well as command line client usage.
Devshell opens a shell where all the OE variables and recipe defines are set. When a build fails, it is often useful to interactively build the part that is failing. Because OE sets up the build environment, it may not be obvious how to quickly reproduce such an environment. This is where the interactive devshell can help you.