(require '[geo.io :as gio])
=> nil
; read-wkt is ok
(gio/read-wkt "POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))")
=> #object[org.locationtech.jts.geom.Polygon 0x223e81a9 "POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))"]
; issue and exception thrown
(gio/to-geojson (gio/read-wkt "POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))"))
Execution error (NoSuchMethodError) at org.wololo.jts2geojson.GeoJSONWriter/convert (GeoJSONWriter.java:79).
'org.locationtech.jts.geom.LineString org.locationtech.jts.geom.Polygon.getExteriorRing()'
Simple fix is perhaps by updating libraries:
locationtech/spatial4j#192