ux: show list of causes for vcs unavailable error page

rhodecode/config/middleware.py

@@ -248,7 +248,6 b' def webob_to_pyramid_http_response(webob'
 
 
 def error_handler(exception, request):
-    # TODO: dan: replace the old pylons error controller with this
     from rhodecode.model.settings import SettingsModel
     from rhodecode.lib.utils2 import AttributeDict
 
@@ -277,6 +276,10 b' def error_handler(exception, request):'
     if not c.rhodecode_name:
         c.rhodecode_name = 'Rhodecode'
 
+    c.causes = []
+    if hasattr(base_response, 'causes'):
+        c.causes = base_response.causes
+
     response = render_to_response(
         '/errors/error_document.html', {'c': c}, request=request,
         response=base_response)

rhodecode/lib/exceptions.py

@@ -127,6 +127,11 b' class VCSServerUnavailable(HTTPBadGatewa'
     """ HTTP Exception class for VCS Server errors """
     code = 502
     title = 'VCS Server Error'
+    causes = [
+        'VCS Server is not running',
+        'Incorrect vcs.server=host:port',
+        'Incorrect vcs.server.protocol',
+    ]
     def __init__(self, message=''):
         self.explanation = 'Could not connect to VCS Server'
         if message:

rhodecode/templates/errors/error_document.html

@@ -39,11 +39,17 b''
                     <p>${_('You will be redirected to %s in %s seconds') % (c.redirect_module,c.redirect_time)}</p>
                 %endif
                 <div class="inner-column">
-                    <h4>Possible Cause</h4>
+                    <h4>Possible Causes</h4>
                     <ul>
+                    % if c.causes:
+                        %for cause in c.causes:
+                            <li>${cause}</li>
+                        %endfor
+                    %else:
                         <li>The resource may have been deleted.</li>
                         <li>You may not have access to this repository.</li>
                         <li>The link may be incorrect.</li>
+                    %endif
                     </ul>
                 </div>
                 <div class="inner-column">