Reposting in general for visibility as it may not only be a Linux only issue:
see original http://libretro.com/forums/showthread.php?t=5359 though no replies just yet.
So a couple odd things I’ve experienced on a fresh Lubuntu 15.10 install:
I setup Retroarch via the stable PPA (retroarch retroarch-* libretro-*) and almost everything was doing good, except every time I set the RGUI to go into fullscreen mode, it would lockup when exiting, but when launching a game directly (no RGUI) in fullscreen it seemed fine, so since I was using a frontend (attractmode) it wasn’t a big deal, set full screen via config and it was working. Tested with SNES cores (snes9x – for some reason bsnes wasn’t working for all games?).
Then, all of a sudden, keyboard input stops working all together in retroarch (cannot exit, quit, etc), turned fullscreen back off, tried debugging, nothing. The ONLY key bind which seems to work was “/” which brought up the search box, which I could then type things in and it would work (tested searching “core” and “content”, it would move to “Load Core” and “Load Content” accordingly).
So I figured something was messed up, removed my config, did a full uninstall and purge, then reinstall, same issue.
Tried switching to the testing branch, same issue.
I tried switching input_driver to sdl2 or linuxraw (from udev) to no avail.
The keyboard itself is a bluetooth keyboard which works fine in the front end, terminal, etc, I’m using the default Lubuntu DM/DE with lightdm + openbox + lxpanel.
HELP!