Comment 3 for bug 1756749

This is https://bugs.launchpad.net/bugs/1603299 - you may be able to work around it by upgrading bs4 via pip: pip install --upgrade beautifulsoup4

Unfortunately this is a bug in a dependency library variety uses, and not a problem in the program itself. Judging by that bug report it looks like there is little interest in backporting a fixed bs4 to xenial, to which there's little I can do.