twisted.protocols.telnet is deprecated.

confirmed.

As workaround set in /etc/apt-proxy/apt-proxy-v2.conf:
port = 9998

I dont know, if it conflict with other services.
Adapt your /etc/apt/sources.list:
deb http://localhost:9998/ubuntu/ gutsy main restricted universe multiverse

And restart apt-proxy:
/etc/init.d/apt-proxy restart

The above comment (confirmed, workaround...port = 9998...) does not seem to apply to this issue (twisted.protocols.telnet is deprecated) Wondering if this workaround is for some other bug?

In looking for how this might apply, I have more to report about this bug. looking at the code, it isn't obvious what to do. it seems twisted module code is causing it:
 python2.5/site-packages/twisted/manhole/telnet.py:8 = from twisted.protocols import telnet

which comes from File "/usr/sbin/apt-proxy", line 16,
            from twisted.manhole.telnet import ShellFactory

looking at /usr/sbin/apt-proxy, ShellFactory gets used at 52 - 64.

from #twisted: (12:39:42 AM) dreid: CarlFK: but the answer is that internet.TCPServer is an IService like the one returned by makeService in twisted.conch.manhole_tap

Which I think means reaplace 52 - 64, with something using makeService.

Is this symptom still reproducible in 8.10?

yes. but the config now hides it:

$ sudo apt-get install apt-proxy
...

juser@averatec:/var/log$ cat apt-proxy.log
2008-11-01 15:15:03-0500 [-] Log opened.
2008-11-01 15:15:03-0500 [-] twistd 8.1.0 (/usr/bin/python 2.5.2) starting up
2008-11-01 15:15:03-0500 [-] reactor class: <class 'twisted.internet.selectreactor.SelectReactor'>
2008-11-01 15:15:03-0500 [-] Changing process name to apt-proxy
2008-11-01 15:15:03-0500 [-] Log opened.
2008-11-01 15:15:03-0500 [-] twistd 8.1.0 (/usr/sbin/apt-proxy 2.5.2) starting up
2008-11-01 15:15:03-0500 [-] reactor class: <class 'twisted.internet.selectreactor.SelectReactor'>
2008-11-01 15:15:03-0500 [-] apt_proxy.apt_proxy.Factory starting on 9999
2008-11-01 15:15:03-0500 [-] Starting factory <apt_proxy.apt_proxy.Factory instance at 0x9e3f52c>
2008-11-01 15:15:03-0500 [-] set uid/gid 106/65534

juser@averatec:/var/log$ grep port /etc/apt-proxy/apt-proxy-v2.conf
;; Server port to listen on
port = 9999
;telnet_port = 9998

enable Debugging remote python console:

juser@averatec:/var/log$ grep port /etc/apt-proxy/apt-proxy-v2.conf
;; Server port to listen on
port = 9999
telnet_port = 9998

/etc/init.d/apt-proxy restart
 * Stopping apt-proxy [ OK ]
 * Starting apt-proxy /usr/lib/python2.5/site-packages/twisted/manhole/telnet.py:8: DeprecationWarning: As of Twisted 2.1, twisted.protocols.telnet is deprecated. See twisted.conch.telnet for the current, supported API.
  from twisted.protocols import telnet
None
/usr/lib/python2.5/site-packages/twisted/manhole/telnet.py:8: DeprecationWarning: As of Twisted 2.1, twisted.protocols.telnet is deprecated. See twisted.conch.telnet for the current, supported API.
  from twisted.protocols import telnet
None

not sure why this was marked incomplete.

same ...

# /etc/init.d/apt-proxy start
 * Starting apt-proxy/usr/lib/python2.5/site-packages/twisted/manhole/telnet.py:8: DeprecationWarning: As of Twisted 2.1, twisted.protocols.telnet is deprecated. See twisted.conch.telnet for the current, supported API.
  from twisted.protocols import telnet
None
/usr/lib/python2.5/site-packages/twisted/manhole/telnet.py:8: DeprecationWarning: As of Twisted 2.1, twisted.protocols.telnet is deprecated. See twisted.conch.telnet for the current, supported API.
  from twisted.protocols import telnet
None

AIGA

Bug is still present in Lucid 10.04:

<snip>
root@lucid:~# /etc/init.d/apt-proxy restart
 * Stopping apt-proxy [ OK ]
 * Starting apt-proxy /usr/lib/python2.6/dist-packages/twisted/manhole/telnet.py:8: DeprecationWarning: As of Twisted 2.1, twisted.protocols.telnet is deprecated. See twisted.conch.telnet for the current, supported API.
  from twisted.protocols import telnet
None
/usr/lib/python2.6/dist-packages/twisted/manhole/telnet.py:8: DeprecationWarning: As of Twisted 2.1, twisted.protocols.telnet is deprecated. See twisted.conch.telnet for the current, supported API.
  from twisted.protocols import telnet
None
</snip>

Nothing serious, but a bit annoying since it clutters up the logs...

I confirm the bug under lucid too.

Debian has removed the package from unstable due to this bug and alternatives are available. This package is not available in Ubuntu releases after Lucid.
See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=576821