Conditional error logging

[mike]

Is there any way this could be implemented?

Perhaps some way to say

error_log off;

or

error_log /var/log/debug.log debug;

but inside of specific server {} or location {} or even if {} blocks?

sometimes I want to debug only one site, and turning on debugging for
the whole server is almost impossible to view/understand.

also, I want to ignore errors when a certain host is accessing (a dumb
load balancer) - that's when I would appreciate an "off" option...

I was able to do this pretty easily in lighttpd (at least the
conditional debugging); not sure if nginx can support this, and if it
-can- support it in the future?