1) Ant 1.9.1 or older is used.
2) A build file imports Clover's tasks from the clover.jar, e.g.:
3) An attempt to run a build fails with an error like:
This is caused by a bug in zip64 implementation and has been fixed in Ant 1.9.2 (release notes).
Upgrade to Ant 1.9.2 or newer.