I would like to learn Clojure and I've downloaded and set up the following gizmos:
- Clojure 1.6.0 from official site;
- Leiningen 2.4.3;
- Cider 0.6.0 from GitHub.
I've got it working. Now I'm trying to print message "Hello, World!", while running Cider from within Emacs:
; CIDER 0.6.0 (Java 1.7.0_65, Clojure 1.6.0, nREPL 0.2.0-beta5)
user> (println "Hello World!")
Hello World!NoSuchMethodError clojure.tools.nrepl.StdOutBuffer.length()I
clojure.tools.nrepl.middleware.session/session-out/fn--7630
(session.clj:43)NoSuchMethodError clojure.tools.nrepl.StdOutBuffer.length()I
clojure.tools.nrepl.middleware.session/session-out/fn--7630 (session.clj:43)
user>
What is this noise all about? When I just run:
$ clojure
;Clojure 1.6.0
user=> (println "Hello, World!")
Hello, World!
nil
everything is fine. When I do it with Leiningen:
$ lein repl
; lotsa stuff here...
user=> (println "Hello, World!")
After entering of this command I relish the following poetry:
CompilerException java.lang.RuntimeException: Unable to resolve symbol: rprintln in this context, compiling:(NO_SOURCE_PATH:1:1) NoSuchMethodError clojure.tools.nrepl.StdOutBuffer.length()I clojure.tools.nrepl.middleware.session/session-out/fn--7630 (session.clj:43)
Exception in thread "nREPL-worker-3" java.lang.NoSuchMethodError: clojure.tools.nrepl.StdOutBuffer.length()I
at clojure.tools.nrepl.middleware.session$session_out$fn__7630.doInvoke(session.clj:43)
at clojure.lang.RestFn.invoke(RestFn.java:460)
at clojure.tools.nrepl.middleware.session.proxy$java.io.Writer$ff19274a.write(Unknown Source)
at java.io.PrintWriter.write(PrintWriter.java:456)
at java.io.PrintWriter.write(PrintWriter.java:473)
at clojure.core$fn__5471.invoke(core_print.clj:191)
at clojure.lang.MultiFn.invoke(MultiFn.java:231)
at clojure.core$pr_on.invoke(core.clj:3392)
at clojure.core$pr.invoke(core.clj:3404)
at clojure.lang.AFn.applyToHelper(AFn.java:154)
at clojure.lang.RestFn.applyTo(RestFn.java:132)
at clojure.core$apply.invoke(core.clj:624)
at clojure.core$prn.doInvoke(core.clj:3437)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.core$apply.invoke(core.clj:624)
at clojure.core$println.doInvoke(core.clj:3457)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.main$repl_caught.invoke(main.clj:158)
at clojure.tools.nrepl.middleware.interruptible_eval$evaluate$fn__7569$fn__7582.invoke(interruptible_eval.clj:76)
at clojure.main$repl$fn__6634.invoke(main.clj:259)
at clojure.main$repl.doInvoke(main.clj:257)
at clojure.lang.RestFn.invoke(RestFn.java:1096)
at clojure.tools.nrepl.middleware.interruptible_eval$evaluate$fn__7569.invoke(interruptible_eval.clj:56)
at clojure.lang.AFn.applyToHelper(AFn.java:152)
at clojure.lang.AFn.applyTo(AFn.java:144)
at clojure.core$apply.invoke(core.clj:624)
at clojure.core$with_bindings_STAR_.doInvoke(core.clj:1862)
at clojure.lang.RestFn.invoke(RestFn.java:425)
at clojure.tools.nrepl.middleware.interruptible_eval$evaluate.invoke(interruptible_eval.clj:41)
at clojure.tools.nrepl.middleware.interruptible_eval$interruptible_eval$fn__7610$fn__7613.invoke(interruptible_eval.clj:171)
at clojure.core$comp$fn__4192.invoke(core.clj:2402)
at clojure.tools.nrepl.middleware.interruptible_eval$run_next$fn__7603.invoke(interruptible_eval.clj:138)
at clojure.lang.AFn.run(AFn.java:22)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Oh, Nooo. What a pain! Stop it, stop it!
I'm so perplexed. What is it and how do I fix this? Has anyone similar experience? How do I print "Hello, World!" in Clojure?
I can reproduce this error with leinengen 2.4.3. You can run lein upgrade 2.4.2 to get the most recent version that actually works. It's unusual for the leiningen team to mark a bad build like this as stable, at first I suspected cider. By the way, the "stable" version of cider should be 0.7.0.
来源：https://stackoverflow.com/questions/25397866/unexpected-difficulties-with-hello-world