...
Wotaskd launches new WOA instances using a script called SpawnOfWotaskd.sh that is located in /System/Library/WebObjects/JavaApplications/wotaskd.woa/Contents/Resources/SpawnOfWotaskd.sh on OS X. For some reason, this script was written to throw away stdout and redirrect stderr to stdout. This means that if you ever want to get a thread stack dump, you're out of luck. Fortunately this is an easy fix. If you edit SpawnOfWotaskd.sh, the stock version looks like:
...