502 errors, upstream sent too big header

[pqdbr]

Guys did you see that Passenger 3.0.8 was released today, with this in
the changelog:

[Nginx] Added the options passenger_buffer_size, passenger_buffers and
passenger_busy_buffers_size. These options are similar to
proxy_module’s similarly named options. You can use these to e.g.
increase the maximum header size limit.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,188352,213356#msg-213356