On Tue, Jan 16, 2018 at 10:59:49AM +0100, Pierre Neidhardt via aur-general wrote:
Seems fairly popular, plus it's useful to lock the screen on sleep without systemd.
I realize I'm somewhat late with this response, but upstream hasn't updated their project in years and the release has several outstanding issues, such as using 100% CPU  and broken features such as the advertised IdleAction support. 
If you use polkit and acpid, a "simple" alternative is to use systemd-inhibit, and run actions based on acpid events. Not sure there's a ready implementation with X support in mind.
Or now that you've adopted it, perhaps you could look over the ~700 lines of C code and fix outstanding issues. :)
 https://bitbucket.org/raymonad/xss-lock/issues/6/hang-high-cpu-on-session-ex...  https://bitbucket.org/raymonad/xss-lock/issues/17/does-not-report-activity-t...