Clojure Q&A - Recent questions in CIDER

how do you set -Djdk.attach.allowAttachSelf enabled so that I can interrupt a cider repl in emacs

Tue, 02 Sep 2025 15:56:27 +0000

In a long running process I want to interrupt the repl.
if you set deps.edn with the following:

:aliases {:dev {:jvm-opts ["-Djdk.attach.allowAttachSelf enabled"
                            "-XX:+PreserveFramePointer"
                            "-XX:+UnlockDiagnosticVMOptions"
                            "-XX:+DebugNonSafepoints"]}}

and then in init.el:

(setq cider-clojure-cli-global-options "-Adev")

you can avoid the following error:

ERROR: Cannot stop thread on JDK21+ without -Djdk.attach.allowAttachSelf 
enabled, see https://nrepl.org/nrepl/installation.html#jvmti.

but the java process still continues

Unable to locate a Java Runtime

Sat, 29 Jul 2023 18:13:11 +0000

I try to learn Clojure and follow Clojure for the Brave and True book.

In core.clj file, I typed M-x cider-jack-in command. I see following error:

error in process sentinel: Could not start nREPL server: The operation couldn’t be completed. Unable to locate a Java Runtime.

I tried both 8 and 17 versions of Java, I verified them via which java and echo $JAVA_HOME

Lein commands works by themselves.

Can you help me?

cider repl error ClassNotFoundException: jdk.javadoc.doclet.Doclet

Thu, 12 Jan 2023 16:06:35 +0000

Hello Everyone,

I have started learning clojure. Using the book "clojure for the brave and true".
I am trying to get the first code running using emacs, cider.

Whenever I run
M-x cider-jack-in

to start the repl. It starts then I get a very long error stack trace.
From the analysis I have done. It appers the error is caused

by Caused by: java.lang.ClassNotFoundException: jdk.javadoc.doclet.Doclet

I am using
jdk 11.0.14
clojure 1.11.1
cider 1.6.0

Find below the stack trace

;; Startup: "c:/Users/nyemi/Documents/clojure/lein.bat" update-in :dependencies conj ^"[nrepl/nrepl \^"1.0.0\^"]^" -- update-in :plugins conj ^"[cider/cider-nrepl \^"0.29.0\^"]^" -- repl :headless :host localhost
ERROR: Unhandled REPL handler exception processing message {:op init-debugger, :nrepl.middleware.print/stream? 1, :nrepl.middleware.print/print cider.nrepl.pprint/pprint, :nrepl.middleware.print/quota 1048576, :nrepl.middleware.print/buffer-size 4096, :nrepl.middleware.print/options {:right-margin 70}, :session d8f7ce4f-e479-4c00-a8c3-2bc4f2bb3257, :id 6}
Syntax error macroexpanding at (cider/nrepl/inlined/deps/orchard/v0v11v0/orchard/java/parser.clj:1:1).

at clojure.lang.Compiler.load(Compiler.java:7665)
at clojure.lang.RT.loadResourceScript(RT.java:381)
at clojure.lang.RT.loadResourceScript(RT.java:372)
at clojure.lang.RT.load(RT.java:459)
at clojure.lang.RT.load(RT.java:424)
at clojure.core$load$fn__6908.invoke(core.clj:6161)
at clojure.core$load.invokeStatic(core.clj:6160)
at clojure.core$load.doInvoke(core.clj:6144)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core$load_one.invokeStatic(core.clj:5933)
at clojure.core$load_one.invoke(core.clj:5928)
at clojure.core$load_lib$fn__6850.invoke(core.clj:5975)
at clojure.core$load_lib.invokeStatic(core.clj:5974)
at clojure.core$load_lib.doInvoke(core.clj:5953)
at clojure.lang.RestFn.applyTo(RestFn.java:142)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$load_libs.invokeStatic(core.clj:6016)
at clojure.core$load_libs.doInvoke(core.clj:6000)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$require.invokeStatic(core.clj:6038)
at clojure.core$require.doInvoke(core.clj:6038)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.lang.Compiler$InvokeExpr.eval(Compiler.java:3714)
at clojure.lang.Compiler$BodyExpr.eval(Compiler.java:6151)
at clojure.lang.Compiler$IfExpr.eval(Compiler.java:2741)
at clojure.lang.Compiler$DefExpr.eval(Compiler.java:457)
at clojure.lang.Compiler.eval(Compiler.java:7199)
at clojure.lang.Compiler.load(Compiler.java:7653)
at clojure.lang.RT.loadResourceScript(RT.java:381)
at clojure.lang.RT.loadResourceScript(RT.java:372)
at clojure.lang.RT.load(RT.java:459)
at clojure.lang.RT.load(RT.java:424)
at clojure.core$load$fn__6908.invoke(core.clj:6161)
at clojure.core$load.invokeStatic(core.clj:6160)
at clojure.core$load.doInvoke(core.clj:6144)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core$load_one.invokeStatic(core.clj:5933)
at clojure.core$load_one.invoke(core.clj:5928)
at clojure.core$load_lib$fn__6850.invoke(core.clj:5975)
at clojure.core$load_lib.invokeStatic(core.clj:5974)
at clojure.core$load_lib.doInvoke(core.clj:5953)
at clojure.lang.RestFn.applyTo(RestFn.java:142)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$load_libs.invokeStatic(core.clj:6016)
at clojure.core$load_libs.doInvoke(core.clj:6000)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$require.invokeStatic(core.clj:6038)
at clojure.core$require.doInvoke(core.clj:6038)
at clojure.lang.RestFn.invoke(RestFn.java:619)
at cider.nrepl.inlined.deps.orchard.v0v11v0.orchard.info$eval4201$loading__6789__auto____4202.invoke(info.clj:1)
at cider.nrepl.inlined.deps.orchard.v0v11v0.orchard.info$eval4201.invokeStatic(info.clj:1)
at cider.nrepl.inlined.deps.orchard.v0v11v0.orchard.info$eval4201.invoke(info.clj:1)
at clojure.lang.Compiler.eval(Compiler.java:7194)
at clojure.lang.Compiler.eval(Compiler.java:7183)
at clojure.lang.Compiler.load(Compiler.java:7653)
at clojure.lang.RT.loadResourceScript(RT.java:381)
at clojure.lang.RT.loadResourceScript(RT.java:372)
at clojure.lang.RT.load(RT.java:459)
at clojure.lang.RT.load(RT.java:424)
at clojure.core$load$fn__6908.invoke(core.clj:6161)
at clojure.core$load.invokeStatic(core.clj:6160)
at clojure.core$load.doInvoke(core.clj:6144)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core$load_one.invokeStatic(core.clj:5933)
at clojure.core$load_one.invoke(core.clj:5928)
at clojure.core$load_lib$fn__6850.invoke(core.clj:5975)
at clojure.core$load_lib.invokeStatic(core.clj:5974)
at clojure.core$load_lib.doInvoke(core.clj:5953)
at clojure.lang.RestFn.applyTo(RestFn.java:142)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$load_libs.invokeStatic(core.clj:6016)
at clojure.core$load_libs.doInvoke(core.clj:6000)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$require.invokeStatic(core.clj:6038)
at clojure.core$require.doInvoke(core.clj:6038)
at clojure.lang.RestFn.invoke(RestFn.java:703)
at cider.nrepl.inlined.deps.haystack.v0v0v3.haystack.analyzer$eval2880$loading__6789__auto____2881.invoke(analyzer.clj:1)
at cider.nrepl.inlined.deps.haystack.v0v0v3.haystack.analyzer$eval2880.invokeStatic(analyzer.clj:1)
at cider.nrepl.inlined.deps.haystack.v0v0v3.haystack.analyzer$eval2880.invoke(analyzer.clj:1)
at clojure.lang.Compiler.eval(Compiler.java:7194)
at clojure.lang.Compiler.eval(Compiler.java:7183)
at clojure.lang.Compiler.load(Compiler.java:7653)
at clojure.lang.RT.loadResourceScript(RT.java:381)
at clojure.lang.RT.loadResourceScript(RT.java:372)
at clojure.lang.RT.load(RT.java:459)
at clojure.lang.RT.load(RT.java:424)
at clojure.core$load$fn__6908.invoke(core.clj:6161)
at clojure.core$load.invokeStatic(core.clj:6160)
at clojure.core$load.doInvoke(core.clj:6144)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core$load_one.invokeStatic(core.clj:5933)
at clojure.core$load_one.invoke(core.clj:5928)
at clojure.core$load_lib$fn__6850.invoke(core.clj:5975)
at clojure.core$load_lib.invokeStatic(core.clj:5974)
at clojure.core$load_lib.doInvoke(core.clj:5953)
at clojure.lang.RestFn.applyTo(RestFn.java:142)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$load_libs.invokeStatic(core.clj:6016)
at clojure.core$load_libs.doInvoke(core.clj:6000)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$require.invokeStatic(core.clj:6038)
at clojure.core$require.doInvoke(core.clj:6038)
at clojure.lang.RestFn.invoke(RestFn.java:1289)
at cider.nrepl.middleware.debug$eval1742$loading__6789__auto____1743.invoke(debug.clj:1)
at cider.nrepl.middleware.debug$eval1742.invokeStatic(debug.clj:1)
at cider.nrepl.middleware.debug$eval1742.invoke(debug.clj:1)
at clojure.lang.Compiler.eval(Compiler.java:7194)
at clojure.lang.Compiler.eval(Compiler.java:7183)
at clojure.lang.Compiler.load(Compiler.java:7653)
at clojure.lang.RT.loadResourceScript(RT.java:381)
at clojure.lang.RT.loadResourceScript(RT.java:372)
at clojure.lang.RT.load(RT.java:459)
at clojure.lang.RT.load(RT.java:424)
at clojure.core$load$fn__6908.invoke(core.clj:6161)
at clojure.core$load.invokeStatic(core.clj:6160)
at clojure.core$load.doInvoke(core.clj:6144)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core$load_one.invokeStatic(core.clj:5933)
at clojure.core$load_one.invoke(core.clj:5928)
at clojure.core$load_lib$fn__6850.invoke(core.clj:5975)
at clojure.core$load_lib.invokeStatic(core.clj:5974)
at clojure.core$load_lib.doInvoke(core.clj:5953)
at clojure.lang.RestFn.applyTo(RestFn.java:142)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$load_libs.invokeStatic(core.clj:6016)
at clojure.core$load_libs.doInvoke(core.clj:6000)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$require.invokeStatic(core.clj:6038)
at clojure.core$require.doInvoke(core.clj:6038)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at cider.nrepl$handler_future$fn__1130$fn__1131.invoke(nrepl.clj:53)
at clojure.lang.AFn.applyToHelper(AFn.java:152)
at clojure.lang.AFn.applyTo(AFn.java:144)
at clojure.core$apply.invokeStatic(core.clj:667)
at clojure.core$with_bindings_STAR_.invokeStatic(core.clj:1990)
at clojure.core$with_bindings_STAR_.doInvoke(core.clj:1990)
at clojure.lang.RestFn.invoke(RestFn.java:425)
at cider.nrepl$handler_future$fn__1130.invoke(nrepl.clj:52)
at clojure.lang.Delay.deref(Delay.java:42)
at clojure.core$deref.invokeStatic(core.clj:2337)
at clojure.core$deref.invoke(core.clj:2323)
at cider.nrepl$wrap_debug$fn__1213.invoke(nrepl.clj:163)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at cider.nrepl$wrap_enlighten$fn__1221.invoke(nrepl.clj:190)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at nrepl.middleware.load_file$wrap_load_file$fn__11240.invoke(load_file.clj:81)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at cider.nrepl$wrap_content_type$fn__1171.invoke(nrepl.clj:107)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at nrepl.middleware.session$add_stdin$fn__10848.invoke(session.clj:379)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at cider.nrepl$wrap_inspect$fn__1247.invoke(nrepl.clj:227)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at nrepl.middleware.caught$wrap_caught$fn__10673.invoke(caught.clj:97)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at cider.nrepl$wrap_profile$fn__1279.invoke(nrepl.clj:343)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at nrepl.middleware.print$wrap_print$fn__10644.invoke(print.clj:234)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at cider.nrepl$wrap_undef$fn__1343.invoke(nrepl.clj:531)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at cider.nrepl$wrap_tracker$fn__1335.invoke(nrepl.clj:520)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at nrepl.middleware.lookup$wrap_lookup$fn__11266.invoke(lookup.clj:52)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at nrepl.middleware.session$session$fn__10835.invoke(session.clj:325)
at nrepl.middleware$wrap_conj_descriptor$fn__10438.invoke(middleware.clj:16)
at nrepl.server$default_handler$fn__11337.invoke(server.clj:141)
at nrepl.server$handle_STAR_.invokeStatic(server.clj:24)
at nrepl.server$handle_STAR_.invoke(server.clj:21)
at nrepl.server$handle$fn__11305.invoke(server.clj:41)
at clojure.core$binding_conveyor_fn$fn__5823.invoke(core.clj:2047)
at clojure.lang.AFn.call(AFn.java:18)
at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)

Caused by: java.lang.ClassNotFoundException: jdk.javadoc.doclet.Doclet

at java.base/java.net.URLClassLoader.findClass(Unknown Source)
at clojure.lang.DynamicClassLoader.findClass(DynamicClassLoader.java:69)

passing command line arguments to clojure via `cider-jack-in` (GNUEmacs 27.1, CIDER 1.2.0)

Wed, 12 Oct 2022 02:16:48 +0000

I want to do cider-jack-in but I want to run with some predefined arguments passed to the clojure executable.

Each time I do a cider-jack-in, I want to pick up my :aliases {:dev {:extra-deps ... :extra-paths ... }} as defined in my deps.edn

Current workaround is to open an xterminal and type,
clj -A:dev
Then from GNUEmacs do cider-connect

Since clj is just wrapping rlwrap around /usr/bin/clojure, i understand I can run clojure via CIDER, but what's the best way to get the argument, -A:dev, passed in, too.

I tried setq'ing various things to the GNUEmacs variable, cider-clojure-cli-aliases without success.

Versions I am using...

CIDER 1.2.0 (Nice)

GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.24, cairo version 1.16.0)
of 2021-03-27, modified by Debian

With Emacs/Cider, what is the way to have local javadocs available?

Wed, 17 Aug 2022 14:07:32 +0000

With Emacs/Cider, what is the way to have local javadocs available? I would already be happy if I had the JDK javadocs.

When I "Press <C-c C-d C-d> to view the documentation for something (e.g. a var, a Java method)"

... with anything Java, I always get "Not documented. For additional documentation, see the Javadoc. Definition location unavailable."

I primarily use Windows and Java 18. But on Linux, I haven't seen it working either.

Among other attempts, I tried:

(use-package cider
   :custom
   (cider-enrich-classpath t)
   (cider-jdk-src-paths '("c:/opt/zulu18.32.11-ca-jdk18.0.2-win_x64/lib/src.zip"))
   ...)

This is all more confusing than helping:

https://docs.cider.mx/cider/usage/working_with_documentation.html#javadoc
https://github.com/clojure-emacs/enrich-classpath
https://github.com/clojure-emacs/cider/issues/930
https://bleepcoder.com/cider/315190809/cider-doesn-t-show-docs-for-java