The LGPL code that came from KDE has been removed back in 2014.
It was replaced with a different implementation, made in
a separate repository.
See commits:
a17caba2c9c2aa5960581db01e4b66472a9c019c
b82eb5873e99dce6aec735b08929e3add52e53e7
* The resulting instance window can be closed at any point.
* Main window is kept open and running instances are marked with a badge.
* Multiple instances can now run from the same MultiMC - it's even more **multi** now.
* MultiMC can be entirely closed, keeping Minecraft(s) running.