at panic (go/src/runtime/panic.go:489)
at main.checkErr (cloudsql.go:40)
at main.censusTracts (cloudsql.go:244)
at net/http.HandlerFunc.ServeHTTP (server.go:1942)
at net/http.(*ServeMux).ServeHTTP (server.go:2238)
at appengine_internal.executeRequestSafely (api_prod.go:296)
at appengine_internal.(*server).HandleRequest (api_prod.go:232)
at reflect.Value.call (value.go:434)