The bug is 100% reproduceable. The game starts fine, I run it from the command line with a wrapper script that changes to factorio/bin/x64 and does exec ./factorio "$@". If I move my mouse away from the factorio window and another window comes into focus, the game hangs. It takes two ctrl-Cs to kill it, though the signal handlers trigger correctly after the first -- the "caught SIGINT" message is printed to the console. Alt-tabbing away, or changing virtual desktop and losing focus that way, does not appear to cause the hang. It is specifically a focus change due to focus following the mouse pointer. And it's not due to my window manager because that last had an update in 2014

The 1.19 changelog is (mostly) here, for your perusal: https://lists.freedesktop.org/archives/ ... 58265.html
I have attached a complete list of installed packages and the output of running strace -ff -o strace ./factorio and then triggering the bug. It's quite large, sorry! I can get you a core dump from a hung game if it'll be helpful, but that will most likely be even bigger.