每当我尝试安装某些东西时，pip都会出现以下错误：
Downloading/unpacking Django>=1.5.1,<1.6 (from -r requirements.txt (line 1))
Downloading Django-1.5.4.tar.gz (8.1MB): 8.0MB downloaded
Cleaning up...
Exception:
Traceback (most recent call last):
File "/vagrant/venv/local/lib/python2.7/site-packages/pip/basecommand.py", line 134, in main
status = self.run(options, args)
File "/vagrant/venv/local/lib/python2.7/site-packages/pip/commands/install.py", line 236, in run
requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
File "/vagrant/venv/local/lib/python2.7/site-packages/pip/req.py", line 1092, in prepare_files
self.unpack_url(url, location, self.is_download)
File "/vagrant/venv/local/lib/python2.7/site-packages/pip/req.py", line 1238, in unpack_url
retval = unpack_http_url(link, location, self.download_cache, self.download_dir)
File "/vagrant/venv/local/lib/python2.7/site-packages/pip/download.py", line 622, in unpack_http_url
download_hash = _download_url(resp, link, temp_location)
File "/vagrant/venv/local/lib/python2.7/site-packages/pip/download.py", line 495, in _download_url
chunk = resp.read(4096)
File "/usr/lib/python2.7/socket.py", line 380, in read
data = self._sock.recv(left)
File "/usr/lib/python2.7/httplib.py", line 561, in read
s = self.fp.read(amt)
File "/usr/lib/python2.7/socket.py", line 380, in read
data = self._sock.recv(left)
File "/usr/lib/python2.7/ssl.py", line 241, in recv
return self.read(buflen)
File "/usr/lib/python2.7/ssl.py", line 160, in read
return self._sslobj.read(len)
SSLError: The read operation timed out
Storing complete log in /home/vagrant/.pip/pip.log这曾经不时发生在我身上，但现在我无法安装任何东西。我尝试添加--timeout=600，但它在相同的时间内失败（达到 8.0M 后几秒钟）。
关于如何解决这个问题的任何想法？