When new developers join a team, or existing developers move quickly between projects, setting up a development environment can be a real headache. Most software teams will (hopefully) share a set of instructions on a wiki that include:
The tools that must be installed (and where to get them). In many projects this should also include the version of the tool that is to be used plus all the dependencies that are required
A set of SCM locations from which to fetch the source code (Git, CVS, SVN, etc…)
Common preferences such as Checkstyle rules, compiler settings, etc…
A set of repositories to fetch ‘target components’ or libraries that are used for development, testing and runtime
If the instructions are up-to-date, then setting up the development environment should go smoothly (assuming that plugins and components are still available, and the new developer is able to understand any acronyms or nuances in the instructions). If the instructions are hard to follow, a developer may spend a day or more just getting started.