Because of libkrb5-dev, I assume I'm using MIT Kerberos. According to the
documentation it should suffice to set the environment
variable KRB5RCACHETYPE=none, but it doesn't work. printenv shows that it
is set, but the replay cache file is still created as /var/tmp/http_33.
Thhe first request is fine, but the logs show that subsequent requests with
the same ticket are causing gss_accept_sec_context() to fail with "Request
is a replay".
Now, I'm not sure if the problem is in MIT Kerberos, the Nginx module, or
my lack of understanding, so I'm looking for any clues and clarifications.