Hi,
just today, jburgess improved the renderd output to show which layer is failing (and apparently doesn't exit renderd at this point), and a related mod_tile change ("it now drops any tile requests for the broken layer and logs another error message for each request").
Since I just restarted renderd for a change in hikebike only to see it crash after a few minutes (which doesn't seem to be due to my style changes), these improvements would be quite handy to have.
Cheers Colin