The procedure seems to work fine except for an error during the “pythonbrew install 2.7.10” part:
Installing distribute into /root/.pythonbrew/pythons/Python-2.7.10
ERROR: Failed to install setuptools. See /root/.pythonbrew/log/build.log to see why.
Skip installation of setuptools.
However, once installed, the letsencrypt-auto command hangs for several minutes. The logs (before stopping the script execution with CTRL-C) have this to say:
2016-10-23 17:28:42,695:DEBUG:certbot.main:Root logging level set at 20
2016-10-23 17:28:42,697:INFO:certbot.main:Saving debug log to /var/log/letsencrypt/letsencrypt.log
2016-10-23 17:28:42,706:DEBUG:certbot.main:certbot version: 0.9.3
2016-10-23 17:28:42,706:DEBUG:certbot.main:Arguments: 
2016-10-23 17:28:42,707:DEBUG:certbot.main:Discovered plugins: PluginsRegistry(PluginEntryPoint#nginx,PluginEntryPoint#standalone,PluginEntryPoint#manual,PluginEntryPoint#webroot,PluginEntryPoint#apache,PluginEntryPoint#null)
2016-10-23 17:28:42,713:DEBUG:certbot.plugins.selection:Requested authenticator None and installer None
I don’t think there’s anything really special about my Debian Squeeze setup in respect of vhosts (they’re all in /etc/apache2/sites-available/) and I don’t need a special Python config apart from Letsencrypt, so I’m not sure what this might be due to.
I have installed certbot in the past and uninstalled it because it was failing (differently but I don’t remember the details).