Hi, I am the qBittorrent maintainer.
This is really puzzling...
Travis-ci.org builds are fine for this(they use ubuntu):
https://travis-ci.org/qbittorrent/qBittorrent/builds/19862306
Even our ppa build it ok(it's now facing unrelated problems):
https://launchpad.net/~hydr0g3n/+archive/qbittorrent-stable/
Also git history that I didn't touch these src lines between 3.1.8. and
3.1.9. They weren't even touched in 3.1.8 too but it built ok on Debian.
Also the error messages are really odd. Most of those function signatures
are given an int (which is a valid function signature) but gcc complains
that they are given a long (for which there isn't a function signature).
