Force Nginx to log error?

[J.R.]

Mmmm... If you set it to debug you would probably get something to pop
up sooner rather than later....

My error log level is set to 'error' and I typically see some ocsp
cert timeouts and the occasional client exceeding my request (rate)
limit settings... Not a lot ends up in the nginx error log (at least
not at the level I use)...

Setting up rate limiting is just a few lines in the config, then you
can hit a page with curl or wget and force it to trigger which would
end up in the error log...

If you have something invalid in your config and do a restart, it will
also write that into the error log...