title: Getting error when renewing vault token
body: <p>We are using HashiCorp's <a href="https://github.com/ianunruh/hvac" rel="nofollow noreferrer">Python SDK</a> to access Vault. And have a simple code to renew the token that calls <code>/v1/auth/token/renew-self</code> Vault API behind the scenes.</p>
  
  <pre><code>   client = hvac.Client(
                          url=credentials['vault_addr'],
                          token = credentials['vault_token'],
                          verify=False) 
     try:
          client.renew_token()
      except Exception as e:
          raise ValueError('Could not renew Vault token')
  </code></pre>
  
  <p>When i make this call, i get this error from the Vault Backend</p>
  
  <blockquote>
    <p>failed to renew entry: policies have changed, not renewing</p>
  </blockquote>
  
  <p>Did a bit of digging in the Vault code and i see this is the source of the exception</p>
  
  <pre><code>if !policyutil.EquivalentPolicies(cert.Policies, req.Auth.Policies) {
      return nil, fmt.Errorf("policies have changed, not renewing")
  }
  </code></pre>
  
  <p>Any ideas ? </p>