More information regarding this issue:
When libxi-dev is not installed, you will find the following error
around the end of CMake's configure step:
-- The following features have been disabled:
* XInput, Required for poll-free mouse cursor updates
When you manually install libxi-dev, which is not included in kwin
build-depends, CMake writes instead:
-- The following features have been enabled:
<...>
* XInput, Required for poll-free mouse cursor updates
* libsystemd, Required for setting up the service watchdog
* libdisplayinfo, EDID and DisplayID library:
https://gitlab.freedesktop.org/emersion/libdisplay-info
<...>
In CMakeLists.txt, you have the following related lines:
add_feature_info("XInput" X11_Xi_FOUND "Required for poll-free mouse
cursor updates")
set(HAVE_X11_XINPUT ${X11_Xinput_FOUND})
I think you also need to add "libxi6" as dependency for kwin-x11 as it
doesn't appear to be the case.
I hope this helps you to solve this issue.
