To> `java -Dhudson.util.ProcessTree.disable=true -jar jenkins.war`
The ProcessTreeKiller takes advantage of the fact that by default a new process gets a copy of the environment variables of its spawning/creating process.
It sets a specific environment variable in the process executing the build job. Later, when the user requests to stop the build job’s process it gets a list of all processes running on the computer and their environment variables, and looks for the environment variable that it initially set for the build job’s process.