Linux: If I start game & debug_enable.txt exists, then my keyboard doesn't work

I've been unable to reproduce this with Fedora 27 and KDE desktop.

Additional info that might be useful:

1) What is your distro, distro version and desktop environment? And what's your window manager (if different than the default for your desktop environment)?

2) Do you have any additional input devices besides keyboard and mouse, like a game controller or graphics tablet?   If so, does the problem go away when the additional input device is disconnected and the game restarted?

3) Are you running the game under anything that would put it in a sandbox or container, like Flatpak or Snappy? If so, does the problem go away when you run it normally?