I'm running a unit test class with 2 tests, and consistently getting this error:

ATAL: Java heap space
java.lang.OutOfMemoryError: Java heap space
at org.jvnet.winp.Native.getCmdLineAndEnvVars(Native Method)
at org.jvnet.winp.WinProcess.parseCmdLineAndEnvVars(WinProcess.java:114)
at org.jvnet.winp.WinProcess.getEnvironmentVariables(WinProcess.java:109)
at hudson.util.ProcessTree$Windows$1.getEnvironmentVariables(ProcessTree.java:321)
at hudson.util.ProcessTree$OSProcess.hasMatchingEnvVars(ProcessTree.java:205)
at hudson.util.ProcessTree$OSProcess.access$200(ProcessTree.java:138)
at hudson.util.ProcessTree$Windows.killAll(ProcessTree.java:341)
at hudson.Launcher$LocalLauncher.kill(Launcher.java:651)
at hudson.model.AbstractBuild$AbstractRunner.run(AbstractBuild.java:276)
at hudson.model.Run.run(Run.java:948)
at hudson.model.Build.run(Build.java:112)
at hudson.model.ResourceController.execute(ResourceController.java:93)
at hudson.model.Executor.run(Executor.java:118)

This does not always happen with the same process.

Setting ProcessTreeKiller.disabled fixes it.

Setting -Xmx128M fixes it too (but this was not necessary before).