gamescope runs its own EIS server and exports the socket to its children as LIBEI_SOCKET —
no portal involved. The gamescope backend now launches the nested app through a tiny shell
wrapper that relays that value to /tmp/lumen-gamescope-ei; the libei injector gains an
EiSource enum (Portal | SocketPathFile) and connects a UnixStream directly to gamescope's
socket (polling until the app has started), then runs the identical reis sender flow.
Backend::GamescopeEi is auto-selected when LUMEN_COMPOSITOR=gamescope
(LUMEN_INPUT_BACKEND=gamescope overrides).
Validated end-to-end: input-test against a headless gamescope running xev — 129
MotionNotify/KeyPress/ButtonPress events delivered into the nested X app ("Gamescope
Virtual Input" device bound, sender handshake + emulation working).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler
7f3897e0d3