Yes, Elia is right. Installing python-requests from unstable will fix the issue. As far as I can tell, it looks like python-urllib3 was already updated, but python-requests was not and is still expecting the old version of urllib. It has been fixed in python-requests (see [1]).
Anyway, this fixes running and building livestreamer: sudo apt install -t unstable python3-requests python-requests I am not sure I can do much to alleviate the issue. I can certainly update the packaging to require a higher python-requests version, but that will make the package just un-installable in testing. Thomas, can you confirm this problem is fixed for you after either install python-requests and python3-requests with 2.9.1-1 or greater? Thanks, Stefan [1] http://metadata.ftp-master.debian.org/changelogs/main/r/requests/requests_2.9.1-1_changelog