No doubt, the new <import> and <macrodef> tasks in Ant 1.6 are a boon when it comes to creating a modular build system and reducing duplication across build files. But the extra level of indirection created by a mixin with an overridden abstract target, for example, can quickly throw you off the trail.
Carefully lay down your machete, brave explorer, before you’re minus one good typing finger, and pick up the Ant Script Visualizer. It lets you visualize how your Ant targets and build files are related to one another by showing all the relationships between imports, targets, macrodefs, taskdefs, etc. Using GraphViz (installed separately), Ant Script Visualizer can generate an Ant target treasure map in PNG and SVN output formats, and PDF on Mac OS X (example outputs). Launch it with Java Web Start to consistently use the freshest version.