java.lang.NullPointerException when starting boot repl -c

[rtacconi]

With openjdk version "12" 2019-03-19 I get

SEVERE: (#error {
 :cause nil
 :via
 [{:type java.lang.NullPointerException
   :message nil
   :at [clojure.core$deref_future invokeStatic core.clj 2292]}]
 :trace
 [[clojure.core$deref_future invokeStatic core.clj 2292]
  [clojure.core$deref invokeStatic core.clj 2312]
  [clojure.core$deref invoke core.clj 2298]
  [cemerick.piggieback$wrap_cljs_repl$fn__12298 invoke piggieback.clj 288]
  [clojure.tools.nrepl.middleware$wrap_conj_descriptor$fn__3333 invoke middleware.clj 22]
  [nrepl.server$handle_STAR_ invokeStatic server.clj 17]
  [nrepl.server$handle_STAR_ invoke server.clj 14]
  [nrepl.server$handle$fn__2813 invoke server.clj 26]
  [clojure.core$binding_conveyor_fn$fn__5476 invoke core.clj 2022]
  [clojure.lang.AFn call AFn.java 18]
  [java.util.concurrent.FutureTask run FutureTask.java 264]
  [java.util.concurrent.ThreadPoolExecutor runWorker ThreadPoolExecutor.java 1128]
  [java.util.concurrent.ThreadPoolExecutor$Worker run ThreadPoolExecutor.java 628]
  [java.lang.Thread run Thread.java 835]]} Unhandled REPL handler exception processing message {:id f4635173-4210-4226-8971-91463e77bc84, :op clone})```