The rubber chicken is apparently used by some sun developers & programmers to avoid “breaking the build” when writing new software or applications.

The rubber chicken creates some social pressure but its silliness removes the sting.

This chicken in this instance would serve the same purpose as a dunce cap. In laymen’s terms, breaking the build is a result of one programmer creating a bug in the code to such a point that nobody else can continue working until that bug is fixed; i.e, the project is now broken. These bugs appear more frequently when many programmers are working on a single project (think opensource), or when you have a very large codebase in which multiple parties are working on.