Description of problem: One of the new features of Mozilla 1.7 touted in the release notes is: "Support for Kerberos HTTP authentication using GSSAPI (benefits Unix-like platforms including Linux and OS X)." To enable this you need to pass --with-gssapi to the configure script during compile. The current spec file doesn't have this. Increasingly the single-sign-on benefits of Kerberos are driving deployments. This feature of Mozilla coupled with mod_auth_kerb for Apache make for a complete open source solution for secure single-sign-on web applications. Please consider making this simple change to the spec file. You probably also want to add krb5-devel to the BuildReq line.
This is already enabled implicitly. The --with-gssapi flag is only required if you have it installed in a weird place. Mozilla finds the correct headers, and if you'll notice, we do build with it (the negotiateauth extension)