Buildout fails: download.zope.org not reachable

@derdritte do you have the complete error traceback on your terminal? More people may have this problem and it would be nice to have this indexed in google.

I tested with a legacy buildout here and got:

An internal error occurred due to a bug in either zc.buildout or in a
recipe being used:
Traceback (most recent call last):
  File "/home/user/instances/buildout-cache/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/buildout.py", line 1995, in main
    getattr(buildout, command)(args)
  File "/home/user/instances/buildout-cache/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/buildout.py", line 666, in install
    installed_files = self[part]._call(recipe.install)
  File "/home/user/instances/buildout-cache/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/buildout.py", line 1410, in _call
    return f()
  File "/home/user/instances/buildout-cache/eggs/plone.recipe.zope2instance-4.2.21-py2.7.egg/plone/recipe/zope2instance/__init__.py", line 113, in install
    installed.extend(self.install_scripts())
  File "/home/user/instances/buildout-cache/eggs/plone.recipe.zope2instance-4.2.21-py2.7.egg/plone/recipe/zope2instance/__init__.py", line 617, in install_scripts
    requirements, ws = self.egg.working_set(['plone.recipe.zope2instance'])
  File "/home/user/instances/buildout-cache/eggs/zc.recipe.egg-1.3.2-py2.7.egg/zc/recipe/egg/egg.py", line 101, in working_set
    **kw)
  File "/home/user/instances/buildout-cache/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/easy_install.py", line 859, in install
    return installer.install(specs, working_set)
  File "/home/user/instances/buildout-cache/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/easy_install.py", line 643, in install
    for_buildout_run=for_buildout_run):
  File "/home/user/instances/buildout-cache/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/easy_install.py", line 488, in _get_dist
    dist, avail = self._satisfied(requirement)
  File "/home/user/instances/buildout-cache/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/easy_install.py", line 253, in _satisfied
    return None, self._obtain(req, source)
  File "/home/user/instances/buildout-cache/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/easy_install.py", line 413, in _obtain
    if index.obtain(requirement) is None:
  File "/home/user/instances/buildout-cache/eggs/setuptools-27.3.0-py2.7.egg/setuptools/package_index.py", line 489, in obtain
    self.prescan()
  File "/home/user/instances/buildout-cache/eggs/setuptools-27.3.0-py2.7.egg/setuptools/package_index.py", line 530, in prescan
    list(map(self.scan_url, self.to_scan))
  File "/home/user/instances/buildout-cache/eggs/setuptools-27.3.0-py2.7.egg/setuptools/package_index.py", line 806, in scan_url
    self.process_url(url, True)
  File "/home/user/instances/buildout-cache/eggs/setuptools-27.3.0-py2.7.egg/setuptools/package_index.py", line 338, in process_url
    f = self.open_url(url, tmpl % url)
  File "/home/user/instances/buildout-cache/eggs/setuptools-27.3.0-py2.7.egg/setuptools/package_index.py", line 745, in open_url
    return open_with_auth(url, self.opener)
  File "/home/user/instances/buildout-cache/eggs/setuptools-27.3.0-py2.7.egg/setuptools/package_index.py", line 946, in _socket_timeout
    return func(*args, **kwargs)
  File "/home/user/instances/buildout-cache/eggs/setuptools-27.3.0-py2.7.egg/setuptools/package_index.py", line 1064, in open_with_auth
    fp = opener(request)
  File "/usr/lib/python2.7/urllib2.py", line 400, in open
    response = self._open(req, data)
  File "/usr/lib/python2.7/urllib2.py", line 418, in _open
    '_open', req)
  File "/usr/lib/python2.7/urllib2.py", line 378, in _call_chain
    result = func(*args)
  File "/usr/lib/python2.7/urllib2.py", line 1207, in http_open
    return self.do_open(httplib.HTTPConnection, req)
  File "/usr/lib/python2.7/urllib2.py", line 1180, in do_open
    r = h.getresponse(buffering=True)
  File "/usr/lib/python2.7/httplib.py", line 1076, in getresponse
    response.begin()
  File "/usr/lib/python2.7/httplib.py", line 444, in begin
    version, status, reason = self._read_status()
  File "/usr/lib/python2.7/httplib.py", line 400, in _read_status
    line = self.fp.readline(_MAXLINE + 1)
  File "/usr/lib/python2.7/socket.py", line 476, in readline
    data = self._sock.recv(self._rbufsize)
timeout: timed out