Looking for the assertion code, a similar bug pops up, with an offset of 2 lines in the source file:
https://bugs.freedesktop.org/show_bug.cgi?id=105275 which duplicates: https://bugs.freedesktop.org/show_bug.cgi?id=105258 That bug is fixed in libinput 1.10.3. I'm currently on 1.10.2-1 so this should improve in the near future. I've disabled the touchpad altogether for now, hoping will prevent the crashes.