Gradle start new process / kill parent session

Question

Background: Apparently, based on JIRA ticket below there are no options to run more than one gradle processes on the same project on the same cache: https://issues.gradle.org/browse/GRADLE-1991

My build contains couple "tasks" that using JavaExec are starting new processes to do some job (not related to build itself). I have more than one of such tasks, and I need to run them in parallel. But cause of issue above - can't

> Could not open buildscript class cache for build file 'C
rpd407vnbbns8c3t51r39r\ProjectScript\buildscript).
   > Timeout waiting to lock buildscript class cache for b...
     Owner PID: unknown
     Our PID: 15860
     Owner Operation: unknown
     Our operation: Initialize cache

What are my options? Ideal solution for me is to run those processes without keeping parent process (let it finish). Is it possible?