change_egid
change_egid(imgp->newcred, attr.va_gid);
change_egid(newcred, gid);
change_egid(newcred, egid);
change_egid(newcred, egid);
change_egid(newcred, egid);
change_egid(new_cred, wcred->sc_gid);
void change_egid(struct ucred *newcred, gid_t egid);