there are dozens of invalid bug reports on "exclude" or "include" e.g. when used nested inside the javac task (Bug 37148, Bug 40718, ..). normally, the recommendation is <<run ant with the -debug option>> and yes, this is likely to help. But it is a nuisance. In particular if your build.xml is a little bit bigger, you possibly spend the first half hour just to find the particular exclude statement you really are after in the overwhelming bulk of debug output. Conclusion, the exclude/include mechanisms are likely to be mature an almost without errors, but average developers waste a lot of time with them to get them right... if the <exclude name=... > tag would have an option parameter 'verbose="true"' that turns on the debug output only when near that tag, searching for my errors when using these tags would be a lot more effective!