Sudo stunnel falha no Kubuntu 15.10 beta

Question

Quando executo o seguinte comando sudo stunnel /etc/stunnel/stunnel.conf , recebo esta mensagem:

[ ] Clients allowed=500
[.] stunnel 5.18 on x86_64-pc-linux-gnu platform
[.] Compiled with OpenSSL 1.0.2a 19 Mar 2015
[.] Running  with OpenSSL 1.0.2c 12 Jun 2015
[.] Update OpenSSL shared libraries or rebuild stunnel
[.] Threading:PTHREAD Sockets:POLL,IPv6,SYSTEMD TLS:ENGINE,FIPS,OCSP,PSK,SNI Auth:LIBWRAP
[ ] errno: (*__errno_location ())
[.] Reading configuration from file /etc/stunnel/stunnel.conf
[.] UTF-8 byte order mark not detected
[.] FIPS mode disabled
[ ] Compression disabled
[ ] Snagged 64 random bytes from /home/username/.rnd
[ ] Wrote 1024 new random bytes to /home/username/.rnd
[ ] PRNG seeded successfully
[!] /etc/stunnel/stunnel.conf:7: "chroot = /var/lib/stunnel4/": Specified option name is not valid here

Com esse outro comando $ systemctl status stunnel4.service , obtenho:

● stunnel4.service - LSB: Start or stop stunnel 4.x (SSL tunnel for network daem
ons)
   Loaded: loaded (/etc/init.d/stunnel4)
   Active: failed (Result: exit-code) since lun. 2015-06-15 15:40:42 CEST; 7min 
ago
     Docs: man:systemd-sysv-generator(8)
  Process: 2460 ExecStart=/etc/init.d/stunnel4 start (code=exited, status=1/FAIL
URE)

juin 15 15:40:42 Kubuntu-VirtualBox stunnel4[2460]: [ ] Compression disabled
juin 15 15:40:42 Kubuntu-VirtualBox stunnel4[2460]: [ ] Snagged 64 random bytes 
from /dev/urandom
juin 15 15:40:42 Kubuntu-VirtualBox stunnel4[2460]: [ ] PRNG seeded successfully
juin 15 15:40:42 Kubuntu-VirtualBox stunnel4[2460]: [!] /etc/stunnel/stunnel.con
f:7: "chroot = /var/lib/stunnel4/": Specified option name is not valid here
juin 15 15:40:42 Kubuntu-VirtualBox stunnel4[2460]: failed (no pid=pidfile speci
fied!)
juin 15 15:40:42 Kubuntu-VirtualBox stunnel4[2460]: You should check that you ha
ve specified the pid= in you configuration file
juin 15 15:40:42 Kubuntu-VirtualBox systemd[1]: stunnel4.service: Control proces
s exited, code=exited status=1
juin 15 15:40:42 Kubuntu-VirtualBox systemd[1]: Failed to start LSB: Start or st
op stunnel 4.x (SSL tunnel for network daemons).
juin 15 15:40:42 Kubuntu-VirtualBox systemd[1]: stunnel4.service: Unit entered f
ailed state.
juin 15 15:40:42 Kubuntu-VirtualBox systemd[1]: stunnel4.service: Failed with re
sult 'exit-code'.

e $ sudo /etc/init.d/stunnel4 restart

[....] Restarting stunnel4 (via systemctl): stunnel4.serviceJob for stunnel4.service failed because the control process exited with error code. See "systemctl status stunnel4.service" and "journalctl -xe" for details.
 failed!

e $ more /etc/stunnel/stunnel.conf

client = no
[squid]
accept = 8888
connect = 127.0.0.1:3128
cert = /etc/stunnel/stunnel.pem

chroot = /var/lib/stunnel4/
setuid = stunnel4
setgid = stunnel4
; PID is created inside chroot jail
pid = /stunnel.pid

; compression = rle
[proxytunnel]
accept = 443
connect = 127.0.0.1:22
TIMEOUTclose = 0

Agradecemos antecipadamente por sua ajuda.

Valorisa