Based on current 2.6.93, building Lustre client on RHEL7 produces a warning related to GSS at configure time.

checking for krb5_derive_key in -lgssapi_krb5... no
checking for gss_export_lucid_sec_context in -lgssapi... no
checking for gss_export_lucid_sec_context in -lgssglue... no
configure: WARNING:

libgssapi or libgssglue is not found, which is required by GSS.

Neither libgssglue or libgssapi exist anymore in EL7, both were replaced by krb5-libs as far as I know.

I tried to fix this but API function names are obviously different, not to mention that I'm not really well versed with that particular API.