When building on Solaris 2.6 sparc, I found that the gssapi.h headers had to be included earlier than rpc/rpc.h because the sub-included <rpc/rpcsec_gss.h> contains this nastiness:

#ifndef _GSSAPI_H_
typedef void * gss_ctx_id_t;
typedef void * gss_cred_id_t;
typedef void * gss_channel_bindings_t;
#endif

I also ended up adding a #define _GSSAPI_H_ kludge because I was building against a 3rd party gssapi library that typedef'd those pointers differently (as pointers to struct, which is what the RFC says) but didn't define _GSSAPI_H_.

This is only a problem on Solaris 2.6.. and not on Solaris 2.8.