We saw this as a recent workshop. Some of our pages have instructions like this:

$ git clone -b alpha https://github.com/flutter/flutter.git
$ export PATH=`pwd`/flutter/bin:$PATH

However, the $ is only there to indicate "command prompt"... and that's not obvious to everyone. Some people copy the entire line and paste it in their console. And the $ isn't meant to be copied and pasted.