First, thanks *so much* for bringing ccache back to active development! I had looked at gocache, but it didn't suite what I was looking for, so like others have minor hacks on top of 2.4 I'm trying to get rid of.
So, I'm experimenting on the git trunk.
Not thinking about how ccache works when renamed, I did effectively this:
cp -p ccache ccache-devel
ccache-prerel: Too many open files
I'm not sure what the right behavior should be, but I doubt this is it. :) I'd suggest setting an env var, and if that env var is set earlier when you're called, it's a recursive loop, so print an error message.
Fixed in 24e6033.