Code 100% stolen from nginx-mod-auth-kerb (https://github.com/fintler/nginx-mod-auth-kerb) which is stolen from mod_auth_gss_krb5 (http://modgssapache.sf.net); version 0.0.5.
It is necessary for sharing common lib (spnego helper) between different packages (nginx-mod-auth-kerb and mod_auth_gss_krb5).