The Collaborative International Dictionary of English v.0.48:

futz \futz\ v. i.
   To fool around; to act without plan or purpose; -- usually
   used with around; as, don't futz around with a device without
   understanding its operation. [Slang.]
   [PJC]

The Free On-line Dictionary of Computing (30 December 2018):

futz

    ("futzing around") To waste time on activity
   that is often experimental and may or may not be
   productive.  Not normally used for game playing.

   (2008-11-27)