AVH reports:

The current version of Runtime.exec(args) prints a couple of
status messages when invoked. Can you please file a bug against it?

pid 18055 status 0
Received sigchild for 18055 exit=0

The description field as copied from bug report 1238421 follows:

The UNIXProcess child cleanup code prints a couple of debugging statements.

Eric Gilbert has already been advised of this bug via e-mail.