Still trying to track down what is causing the following to be logged in the error log:

2012/02/21 10:42:13 [error] 13884#0: *19 testing "/srv/www/users/foobar/wp" existence failed (2: No such file or directory) while logging request, client: X.X.X.X, server: ~^(?<user>.+)\.mydomain\.com$, request: "GET / HTTP/1.1", host: "foobar.pagelines.com"

I believe the problem is since I am configuring the server_name and root dynamically:

server_name ~^(?<user>.+)\.mydomain\.com$;
root /srv/www/users/$user/wp;

And obviously the root directory does not exist for foobar. Is there a way to suppress these errors, or maybe check if the root directory exists?