The step as written said this:
./doStuff.pl --tag=KERMIT --target=/tmp/foo
The script had been updated since I wrote the instructions, and the guy using it got this error:
./doStuff.pl --tag=KERMIT --log=/tmp/foo
Unknown option: --target
Were the instructions wrong? Absolutely.
Should this be something that requires my intervention to solve? Nope.
Reading the error makes it pretty obvious what likely happened: the log option got renamed to logDir somewhere along the way. It's a pretty good idea to try using logDir instead of log - it's got a good chance of working.
Help yourself. Read the error and see if you can solve it. If you can't, go ask for help. But at least read the error and try to help yourself first.