title: what is the right way to query a 2dsphere index to get results sorted by nearest-first with max_distance?
body: <pre><code>&gt; version()
  version: 2.0.4
  can't find special index: 2d for: { location: { $near: { $geometry: { type: "Point", coordinates: [ 0.1, 0.1 ] } }, $maxDistance: 5000.0 } }
  &gt; version()
  version: 2.0.4
  can't find special index: 2d for: { location: { $near: { $geometry: { type: "Point", coordinates: [ 0.1, 0.1 ] } }, $maxDistance: 5000.0 } }
  &gt; db.syncsnapshotsphere.find()
  { "_id" : "naga", "location" : { "type" : "Point", "coordinates" : [ 0.1, 0.1 ] }, "timestamp" : 1375778757.568005 }
  { "_id" : "nagb", "location" : { "type" : "Point", "coordinates" : [ 0.2, 0.2 ] }, "timestamp" : 1375778792.552187 }
  { "_id" : "nagc", "location" : { "type" : "Point", "coordinates" : [ 0.3, 0.3 ] }, "timestamp" : 1375778803.047879 }
  { "_id" : "nagd", "location" : { "type" : "Point", "coordinates" : [ 0.4, 0.4 ] }, "timestamp" : 1375778814.088595 }
  &gt; db.syncsnapshotsphere.find({location: {$near: {$geometry: {type: "Point", coordinates: [0.1,0.1]}}, $maxDistance: 5000}})
  error: {
      "$err" : "can't find special index: 2d for: { location: { $near: { $geometry: { type: \"Point\", coordinates: [ 0.1, 0.1 ] } }, $maxDistance: 5000.0 } }",
      "code" : 13038
  }
  </code></pre>
  
  <p>The weird looking "cant find special index..." soon after the second line "version..." is actually the output... I don't know why.</p>
  
  <p>I am trying to figure out why I get the error saying that it is trying to find a 2d index where as a 2dsphere index already exists on the location field... All help is appreciated.</p>
  
  <pre><code>&gt; db.syncsnapshotsphere.getIndexes()
  [
      {
          "v" : 1,
          "key" : {
              "_id" : 1
          },
          "ns" : "logging_stuff.syncsnapshotsphere",
          "name" : "_id_"
      },
      {
          "v" : 1,
          "key" : {
              "location" : "2dsphere"
          },
          "ns" : "logging_stuff.syncsnapshotsphere",
          "name" : "location_2dsphere",
          "background" : false,
          "dropDups" : false
      }
  ]
  &gt; 
  </code></pre>