title: github error on create release: tag could not be created, pre-receive hooks failed
body: <p>I am not by any means a sophisticated github user.  I have learned the minimum handful of commands needed to add, commit, and push my project code to the public github.com repository.  So far it's been working fairly well... until today when I tried to create a new release (my third).</p>
  
  <p>For some reason, when I try to publish my new release, I get the message</p>
  
  <p><strong>Tag could not be created. Pre-receive hooks failed.</strong></p>
  
  <p>I have never seen this message before.</p>
  
  <p>I have tried various different tag names;  I have tried logging out and back in again;  I have tried pre-tagging on my local disk copy of the repo;  I have pushed and pulled (both ends are up to date).  This about exhausts my repertoire of things to try :-(</p>
  
  <p>As a relative n00b I find this message incredibly opaque (sigh).  I have tried googling for it, but quickly got in over my head -- most of the hits I found were discussions about people setting up their own networked repos and installing or tweaking their own custom "pre-receive hooks", whereas I am just a dumb user of github.com apparently struggling with whatever "pre-receive hooks" they have installed (?).  If anyone can at least point me in the right direction I'd be most grateful.</p>