We have a production tile server loaded using osm2pgsql serving osm-bright, osm-carto and osm-mapquest style tiles and would like to be able to server those in WGS84 projection, as well.
I've tried in vain to update the XML files properly but Mapnik doesn't seem to recognize any of the Map.SRS definitions.
Most recently, per instructions at the Mapnik XMLConfigReference page I've tried using a map srs of
+proj=latlong+datum=WGS84 which resulted in this error:
An error occurred while loading the map layer 'osmcartoproj': failed to initialize projection with: '+proj=latlong+datum=WGS84 +no_defs' in Map at line 4 of '/usr/local/share/maps/style/osmreproj/osmreproj.xml'
Can anyone shed any light on the correct SRS for generating tiles in WGS84?