It would be quite useful to have the revision number of the source code available as an Ant variable.
Imagine a scenario where I have an Ant task as part of my build to tag my SVN repository when my test
suite passes. Without knowing which revision I am currently using I end up using HEAD to create a tag.
But inbetween starting the test suite and a successful test run, someone else could've checked in
changes that will later break the build. Because I tag using HEAD I tag their new (and untested) changes
An alternative to providing the SVN revision number to Ant would be to provide a configuration option
to automatically tag the build after a successful run, essentially automating the functionality added in