Help with strange bzr connection hangs

Mon Oct 3 17:19:48 UTC 2011

I realize that this might not be entirely relevant to bzr, but since
the problem happens while communicating with bzr server, I thought
someone here could help.  And I desperately need help, as I've run out
of ideas.

Here's the thing: sometimes bzr hangs half way through "bzr update"
from bzr.savannah.gnu.org.  It just sits there waiting for something,
with no network traffic at all.  "netstat" shows the connection:

    TCP    home-c4e4a596f7:2700   vcs.savannah.gnu.org:22  ESTABLISHED

but nothing happens.  It doesn't respond to Ctrl-C (this is on
Windows), the only way to stop it is to kill it (using PsKill, for
example).

If I use -Dhpss, I see it always stuck at this point in .bzr.log:

  8.391  Using fetch logic to copy between RemoteRepository(bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/.bzr/)(RemoteRepositoryFormat(_network_name='Bazaar repository format 2a (needs bzr 1.16 or later)\n')) and CHKInventoryRepository('file:///D:/gnu/bzr/emacs/.bzr/repository/')(RepositoryFormat2a())
  8.391  fetching: <SearchResult search:(set(['monnier at iro.umontreal.ca-20111003164956-3dygzh7jbf2k7p9y']), ['rgm at gnu.org-20110820221427-6vbkv2xevrd471fe', 'schwab at linux-m68k.org-20110919211547-bpacfe5tvruisv4p', 'eggert at cs.ucla.edu-20110930202201-vgrjezzuzvexthki', 'cyd at stupidchicken.com-20111001184722-kxn1g5qh5mt3a20a', 'cyd at stupidchicken.com-20110830223807-hqjgxlax2rj3zedr', ...], 8)>
  8.406  hpss call w/body: 'Repository.get_stream_1.19', 'emacs/', 'Bazaar repository format 2a (needs bzr 1.16 or later)\n' ('search\nmonnier at iro.u'...)
  8.406                2310 bytes
  8.672     result:   ('ok',)

The full log up to this point is at the end of this message.

Sometimes, the problem disappears after some time, sometimes it only
disappears after a reboot (or maybe I get impatient and reboot before
it disappears).  Lately, a day or two after a system restart, it
starts happening again.

Other communications, including Web browser SSH to the same host, work
fine, even if these hangs happen.

What could possibly cause this?  Did someone else ever see something
similar?  What should I try to solve this annoyance?

In case it's important, I have AVG 2011 and Comodo firewall on this
machine.  (I have them for a long time, much longer than this
problem.)  Could they interfere in some way?  Are there any known
incompatibilities with these two?

Thanks in advance for any help.

Here's the typical portion of .bzr.log:

 Mon 2011-10-03 19:05:14 +0200
 0.109  bazaar version: 2.4.1
 0.109  bzr arguments: [u'-Dhpss', u'up']
 0.156  looking for plugins in C:/Documents and Settings/Zaretzky/Application Data/bazaar/2.0/plugins
 0.156  looking for plugins in D:/usr/Bazaar/plugins
 0.297  encoding stdout as sys.stdout encoding 'cp1252'
 0.344  opening working tree 'D:/gnu/bzr/emacs/trunk'
 0.375  hpss: Built a new medium: SmartSSHClientMedium
 0.375  hpss call:   'BzrDir.open_2.1', 'emacs/trunk/'
 0.375               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 0.625  falling back to default implementation
 0.625  failed to load system host keys: [Errno 2] No such file or directory: 'D:\\usr\\eli/.ssh/known_hosts'
 [ 3184] 2011-10-03 19:05:15.812 INFO: Connected (version 2.0, client OpenSSH_5.5p1)
 1.719  Trying SSH agent key A6442B38A7FDA45B6B2E3B70568448C5
 [ 3184] 2011-10-03 19:05:17.217 INFO: Authentication (publickey) successful!
 [ 3184] 2011-10-03 19:05:17.453 INFO: Secsh channel 1 opened.
 3.203     result:   ('yes', 'no')
 3.203  hpss call:   'BzrDir.open_branchV3', 'emacs/trunk/'
 3.203               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 3.516     result:   ('branch', 'Bazaar Branch Format 7 (needs bzr 1.6)\n')
 3.516  hpss call:   'BzrDir.find_repositoryV3', 'emacs/trunk/'
 3.516               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 3.719     result:   ('ok', '..', 'yes', 'no', 'yes', 'Bazaar repository format 2a (needs bzr 1.16 or later)\n')
 3.719  hpss call:   'BzrDir.open_2.1', 'emacs/'
 3.719               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 3.937     result:   ('yes', 'no')
 3.937  hpss call:   'BzrDir.find_repositoryV3', 'emacs/'
 3.937               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 4.156     result:   ('ok', '', 'yes', 'no', 'yes', 'Bazaar repository format 2a (needs bzr 1.16 or later)\n')
 4.156  hpss call:   'Repository.is_shared', 'emacs/'
 4.156               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 4.406     result:   ('yes',)
 4.422  hpss call:   'Branch.get_stacked_on_url', 'emacs/trunk/'
 4.422               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 4.656     result:   ('NotStacked',)
 4.703  hpss call:   'BzrDir.open_2.1', 'emacs/trunk/'
 4.703               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 4.984     result:   ('yes', 'no')
 4.984  hpss call:   'BzrDir.open_branchV3', 'emacs/trunk/'
 4.984               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 5.203     result:   ('branch', 'Bazaar Branch Format 7 (needs bzr 1.6)\n')
 5.203  hpss call:   'BzrDir.find_repositoryV3', 'emacs/trunk/'
 5.203               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 5.422     result:   ('ok', '..', 'yes', 'no', 'yes', 'Bazaar repository format 2a (needs bzr 1.16 or later)\n')
 5.422  hpss call:   'BzrDir.open_2.1', 'emacs/'
 5.422               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 5.625     result:   ('yes', 'no')
 5.625  hpss call:   'BzrDir.find_repositoryV3', 'emacs/'
 5.625               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 5.828     result:   ('ok', '', 'yes', 'no', 'yes', 'Bazaar repository format 2a (needs bzr 1.16 or later)\n')
 5.828  hpss call:   'Repository.is_shared', 'emacs/'
 5.828               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 6.062     result:   ('yes',)
 6.062  hpss call:   'Branch.get_stacked_on_url', 'emacs/trunk/'
 6.062               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 6.266     result:   ('NotStacked',)
 6.281  hpss call:   'Branch.last_revision_info', 'emacs/trunk/'
 6.281               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 6.516     result:   ('ok', '105992', 'monnier at iro.umontreal.ca-20111003164956-3dygzh7jbf2k7p9y')
 6.531  hpss call:   'Branch.get_config_file', 'emacs/trunk/'
 6.531               (to bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/trunk/)
 6.750     result:   ('ok',)
 6.750                133 body bytes read
 6.750  hpss call w/body: 'Repository.get_parent_map', 'emacs/', 'include-missing:', 'monnier at iro.umontreal.ca-20111003164956-3dygzh7jbf2k7p9y' ('\n\n0'...)
 6.750                3 bytes
 7.719     result:   ('ok',)
 8.234                61715 body bytes read
 8.391  Using fetch logic to copy between RemoteRepository(bzr+ssh://eliz@bzr.savannah.gnu.org/emacs/.bzr/)(RemoteRepositoryFormat(_network_name='Bazaar repository format 2a (needs bzr 1.16 or later)\n')) and CHKInventoryRepository('file:///D:/gnu/bzr/emacs/.bzr/repository/')(RepositoryFormat2a())
 8.391  fetching: <SearchResult search:(set(['monnier at iro.umontreal.ca-20111003164956-3dygzh7jbf2k7p9y']), ['rgm at gnu.org-20110820221427-6vbkv2xevrd471fe', 'schwab at linux-m68k.org-20110919211547-bpacfe5tvruisv4p', 'eggert at cs.ucla.edu-20110930202201-vgrjezzuzvexthki', 'cyd at stupidchicken.com-20111001184722-kxn1g5qh5mt3a20a', 'cyd at stupidchicken.com-20110830223807-hqjgxlax2rj3zedr', ...], 8)>
 8.406  hpss call w/body: 'Repository.get_stream_1.19', 'emacs/', 'Bazaar repository format 2a (needs bzr 1.16 or later)\n' ('search\nmonnier at iro.u'...)
 8.406                2310 bytes
 8.672     result:   ('ok',)