static output downloads garbage

[rqhub]

youtube-dl http://foo.bar -o "%(id)s.%(ext)s"
works fine

however, for some reason, these download 30 mb's that are unreadable
youtube-dl http://foo.bar -o "video.%(ext)s"
youtube-dl http://foo.bar -o "video.mp4"

any clue ?

[dstftw]

How to report bugs.

[phihag]

http://foo.bar is not a valid URL. As @dstftw noted, please post the output you get when you run youtube-dl with the -v option.