You must create a file named /etc/shells (this is the real /etc not a
subdirectory of your false root), that contains all the shells that
are defined on your system.  Get the list from
/etc/security/login.cfg.  Also, if having proper group authentication
is important to you, apply the following patch:

--- ftpd.c.dist	Wed Apr 13 15:17:18 1994
+++ ftpd.c	Tue Jan 17 13:29:58 1995
@@ -1153,7 +1153,13 @@
        setgroups(NULL, NULL);
        if (setpriv(PRIV_SET|PRIV_INHERITED|PRIV_EFFECTIVE|PRIV_BEQUEATH,
                    &priv, sizeof(priv_t)) < 0 ||
-           setuidx(ID_REAL|ID_EFFECTIVE, (uid_t)pw->pw_uid) < 0 ||
+           initgroups(pw->pw_name, (gid_t)pw->pw_gid) < 0 ||
+           setgidx(ID_REAL|ID_EFFECTIVE, (gid_t)pw->pw_gid) < 0 ||
+           setegid((gid_t)pw->pw_gid) < 0) {
+               reply(550, "Can't set gid (AIX3).");
+               goto bad;
+       }
+       if (setuidx(ID_REAL|ID_EFFECTIVE, (uid_t)pw->pw_uid) < 0 ||
            seteuid((uid_t)pw->pw_uid) < 0) {
                reply(550, "Can't set uid (AIX3).");
                goto bad;

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