I'm using GTP-4 and it makes trivial errors all the time.
I asked it (actual names changed):
"I run the Linux command line program "foo". When I use the flags -xyz, I get results, but when I use -txyz I get nothing. What could this mean?"
And it told me: "The lack of results is because you didn't use the -t flag".
Or I ask it some very basic music theory questions and it gets stuff wrong all the time, giving impossible answers.