title: Mercurial - Ways to resolve abort: error: '' after an hg in/pull
body: <p>A perfectly good repository goes pear shaped after an unknown time.<br>
  A simple <strong>hg in</strong> fails with an error<br>
  <strong>abort: error: ''</strong></p>
  
  <p>Sometimes it just hangs for a few minutes without any output.</p>
  
  <p>If I run with <strong>--verbose</strong>, same output.<br>
  If I run with <strong>--traceback</strong>, I get:  </p>
  
  <pre><code>Traceback (most recent call last):
    File "mercurial\dispatch.pyo", line 88, in _runcatch
    File "mercurial\dispatch.pyo", line 740, in _dispatch
    File "mercurial\dispatch.pyo", line 514, in runcommand
    File "mercurial\dispatch.pyo", line 830, in _runcommand
    File "mercurial\dispatch.pyo", line 801, in checkargs
    File "mercurial\dispatch.pyo", line 737, in &lt;lambda&gt;
    File "mercurial\util.pyo", line 471, in check
    File "mercurial\commands.pyo", line 3901, in incoming
    File "mercurial\hg.pyo", line 513, in incoming
    File "mercurial\hg.pyo", line 472, in _incoming
    File "mercurial\bundlerepo.pyo", line 342, in getremotechanges
    File "mercurial\discovery.pyo", line 45, in findcommonincoming
    File "mercurial\setdiscovery.pyo", line 184, in findcommonheads
    File "mercurial\wireproto.pyo", line 116, in plain
    File "mercurial\wireproto.pyo", line 164, in _submitone
    File "mercurial\httppeer.pyo", line 170, in _call
    File "mercurial\httppeer.pyo", line 118, in _callstream
    File "urllib2.pyo", line 400, in open
    File "urllib2.pyo", line 418, in _open
    File "urllib2.pyo", line 378, in _call_chain
    File "mercurial\url.pyo", line 314, in http_open
    File "mercurial\keepalive.pyo", line 257, in do_open
  URLError: &lt;urlopen error ''&gt;
  abort: error: ''
  </code></pre>
  
  <p>No further details...<br>
  Does anyone have an idea how to debug this and resolve this? I end up cloning the parent repository again and deleting the old one :-(</p>
  
  <p><strong>EDIT:</strong> An update - while having these errors, we were working with two LAN networks that had a link between them. Some of the users where in an "old" network and others in the "new" one.<br>
  After everyone migrated to the new network, we stopped having these errors.</p>
  
  <p>I hope this helps.</p>