CouchDB view does not finish

[Iñigo Sola Núñez]

I have the following view:

{
  "_id": "_design/ofertas",
  "_rev": "1-9556bdbb5fdab8c61d340d44bc9083ea",
  "language": "javascript",
  "views": {
                "byMunicipio": {
                                       "map": "function(doc) {
emit(doc.ciudad, doc); }"
                                      }
               }
}

When I use that view, it never finishs and doesn't show anything.