I was not able to find a simple way to use wp-super-cache with lighttpd, some were using 100 lines lua script and the others were unreliable at best. After an hour of fiddling, I came with the following configuration.
What it does:
i just tried your configuration and kept getting error 500 after a while. Had the same problem with rewrite.lua and by using the php cache variant. Do you got a clue why this happens?
i'm hosting multiple websites on my server and only www.jevermeister.de stopped working after ~5 minutes with an error 500 until i restarted lighttpd.
Jan aka Jevermeister