Hi, has anyone come across this before? This setup was previously working fine but now I get the below error when trying to open any ClojureScript file in vim (vim-fireplace). I am using cider-nrepl 0.21.1 and piggieback 0.4.0. I imagine there might be a version mismatch or something but I am not sure where.

Exception in thread "nRepl-session-b1e1107c-001d-4433-8db7-e66291d821f2" java.lang.IllegalArgumentException: No implementation of method: :send of protocol: #'nrepl.transport/Transport found for class: nil
        at clojure.core$_cache_protocol_fn.invokeStatic(core_deftype.clj:583)
        at clojure.core$_cache_protocol_fn.invoke(core_deftype.clj:575)
        at nrepl.transport$eval48462$fn__48463$G__48453__48470.invoke(transport.clj:16)
        at nrepl.middleware.print$replying_PrintWriter$fn__48919.invoke(print.clj:115)
        at nrepl.middleware.print.proxy$java.io.Writer$ff19274a.write(Unknown Source)
        at java.io.BufferedWriter.flushBuffer(BufferedWriter.java:129)
        at java.io.BufferedWriter.flush(BufferedWriter.java:253)
        at java.io.PrintWriter.newLine(PrintWriter.java:482)
        at java.io.PrintWriter.println(PrintWriter.java:629)
        at java.io.PrintWriter.println(PrintWriter.java:757)
        at java.lang.Throwable$WrappedPrintWriter.println(Throwable.java:764)
        at java.lang.Throwable.printStackTrace(Throwable.java:655)
        at java.lang.Throwable.printStackTrace(Throwable.java:721)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at clojure.lang.Reflector.invokeMatchingMethod(Reflector.java:93)
        at clojure.lang.Reflector.invokeInstanceMethod(Reflector.java:28)
        at cljs.repl$repl_caught.invokeStatic(repl.cljc:809)
        at cljs.repl$repl_caught.invoke(repl.cljc:795)
        at cider.piggieback$repl_caught.invokeStatic(piggieback.clj:105)
        at cider.piggieback$repl_caught.invoke(piggieback.clj:98)
        at cider.piggieback$do_eval.invokeStatic(piggieback.clj:265)
        at cider.piggieback$do_eval.invoke(piggieback.clj:227)
        at cider.piggieback$evaluate.invokeStatic(piggieback.clj:273)
        at cider.piggieback$evaluate.invoke(piggieback.clj:271)
        at clojure.lang.Var.invoke(Var.java:381)
        at cider.piggieback$wrap_cljs_repl$fn__49637$fn__49640$fn__49641.invoke(piggieback.clj:305)
        at cider.piggieback$enqueue$fn__49609.invoke(piggieback.clj:195)
        at clojure.lang.AFn.run(AFn.java:22)
        at nrepl.middleware.session$session_exec$main_loop__49154$fn__49158.invoke(session.clj:171)
        at nrepl.middleware.session$session_exec$main_loop__49154.invoke(session.clj:170)
        at clojure.lang.AFn.run(AFn.java:22)
        at java.lang.Thread.run(Thread.java:748)

I think @pez mentioned a similar problem (take a look at this history).

Yes, I've seen it often with the dev build of Calva, which seems to provoke this thing often. I have failed to trace it down, though.

I haven’t been able to reproduce it, though.

The history is eaten by the 10K monster.

Ah, damn it. My best guess is that the problem happens only with a certain format of the evaluation requests, as no CIDER users have ever reported this.

@cichli helped me with this before

It might be fixed in snapshot piggieback?

He hasn’t been around much lately, but he’s definitely the expert on this part of the code.

My theory has been that it is provoked by something that happens before the evaluation request.

One thing that comes to mind is that CIDER uses streamed values by default. I wonder if the problem happens only without them.

> It might be fixed in snapshot piggieback?

Good idea. @cichli did some refactorings there, although I don’t think anything related to bug reports.

I shall see if it is still easy to get this with Calva, if so I can also check wether snapshot fixes it.

I am hitting the problem consistently, I have just tried with piggieback 0.4.1-SNAPSHOT and the issue went away. Will keep trying and see how I get on.

I did look at the diff between 0.4.0 and 0.4.1-SNAPSHOT and it looked like nothing there could resolve it, it looks like it has though.

@markwoodhall That’s an unexpected, but welcome development. I can cut a release for 0.4.1 is a day or two. Let’s just make sure that the problem goes away for good.

Ah, I’m pretty sure that’s the bug fix https://github.com/nrepl/piggieback/commit/f43e12c13725e2bd31b944d39a55b38dd6b5587c

In light of this revelation I’ve just released 0.4.1 right away. I’m just sorry poor @pez wasted a ton of time debugging this, before @dominicm saved us.

Haha, I learnt a lot in the process, shed no tears my way. ❤️