While developing the script to integrate CJK fonts into GhostScript, we found a strange discrepancy between different versions of GhostScript. With the Yu fonts as distributed with OSX, newer versions of GhostScript crash, while my relatively old version on Debian worked without a problem.
The obvious solution: git bisect!
Fortunately GhostScript is developed in a git repository, so I dived into a git bisect session. For those who don’t know it, git is a distributed, no – it is the distributed revision control system, and adopted more or less by any mayor development team.