Github user leventov commented on the issue:
https://github.com/apache/zookeeper/pull/490
@anmolnar if you try to run `ant test` while the test are not compiled yet
(i. e. they have to be compiled), and Ant uses Java 7 which is installed on
your machine for compilation, yes, this is expected that it will fail. You
would need to run with Java 8.
However, I see that `javac.source` and `javac.target` in `build.xml`
already set to 1.8, how do you test it with Java 7 anyway?---
