When libreoffice builds with postgres support enabled, it checks to be sure that postgres supports kerberos and fails if it is does not. Reproducible: Always
Created attachment 320758 [details] build log
If I install virtual/krb5, libreoffice builds successfully. If I disable the postgres USE flag on libreoffice, libreoffice builds successfully. I do not have enough knowledge to test whether libreoffice's database functionality is fully functional with postgres is installed with USE=-kerberos.
*** This bug has been marked as a duplicate of bug 430568 ***