Test failed because of 'Forked Java VM exited abnormally.'

Sometimes tests fail with error message like this:

Error Message:
Forked Java VM exited abnormally. Please note the time in the report does not reflect the time until the VM exit.

Stack Trace:
junit.framework.AssertionFailedError: Forked Java VM exited abnormally. Please note the time in the report does not reflect the time until the VM exit.

Examples:
https://builds.apache.org/job/ZooKeeper-trunk-solaris/1239/
https://builds.apache.org/job/ZooKeeper_branch34_openjdk7/1147/
https://builds.apache.org/job/ZooKeeper_branch34_openjdk7/1129/

The failure happen on all platforms (jdk7/8/solaris) of branch 3.4; branch 3.5 looks ok in general.