$ youtube-dl -f 18 --verbose https://www.youtube.com/watch?v=USg3NR76XpQ [debug] System config: [] [debug] User config: [u'--netrc', u'--add-metadata', u'--user-agent', u'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:53.0) Gecko/20100101 Firefox/53.0', u'--add-header...