In the previous, simple example, we printed a fortune cookie to the build log.
While this exercise can't be compared in complexity with managing real builds, we at least learned to install and start Jenkins, and if you had issues installing the fortune utility, you got a glimpse of the dark underbelly of managing a CI server: managing the build dependencies.
Some build systems, such as the Maven tool, are nice in the way that the Maven POM file contains descriptions of which build dependencies are needed, and they are fetched automatically by Maven if they aren't already present on the build server. Grunt works in a similar way for JavaScript builds. There is a build description file that contains the dependencies required for the build. Golang builds can even contain links to GitHub repositories required for completing the build.
C and C...