if somebody wants a "C lang/linux level" bug/puzzle to figure out (could be as simple as looking at the source), I just discovered it a couple days ago: if you use a large number to set up a board in untangle, the algo is extremely slow to set the board up, probably an O(N*2) or worse or something. You can see this slowness in the web version, put in a 600 or 2000

the bug: anyway, I was running the C version of the puzzle from cli (didn't want to slow my browser down) and I must have put a typo in for an even bigger number than I intended and the process went away for a long time. I got sick of looking at the little window and discovered that I couldn't kill it even with kill -9. I killed the window with xkill but the process was still chugging away in the background at 99% CPU.

I finally managed to kill it with htop but I have a sense that I didn't really kill it, I think it just finished whatever long ops it was doing.

I didn't test much more, but I did load up a board size 600 to play and confirmed while it was building the board, kill -9 didn't do anything, and after it finished it allowed me to play the game. the kill -9 was swallowed and gone.