JFYI, copying poem.txt from 12.2 Reading a File opened in Chrome into VSCode does not produce utf-8 file but the text apostrophes are non-ASCII character ’. (Is this written in Word?)

The sample code subsequently panicked with stream did not contain valid UTF-8.

Converting poem.txt to utf-8 fixed the issue here. Getting rid of the Unicode apostrophes will fix it for everyone else using VSCode in first place.