cljs quick start failed to locate namespace - clojurescript

Question

I tries to quick start cljs, but the similar problem occurred.
clojure 1.10.3 on linux openjdk 17.0.1
project folder:
.
|_ deps.edn
|_ src
|_ helloworld
|_ core.cljs
core.cljs:
(ns helloworld.core)
(println "helloworld")
deps.edn
{:deps {org.clojure/clojurescript {:mvn/version "1.10.758"}}}
tried to quick start under the project folder but failed,
$ clj -M -m cljs.main -c helloworld.core
Unexpected error (IllegalArgumentException) compiling at (REPL:1).
Namespace helloworld.core does not exist.
#EDIT However, tried on lein-cljsbuild successfully.
$ lein cljsbuild once
project.clj (instead of deps.edn):
(defproject helloworld "0.1.0"
:dependencies [[org.clojure/clojure "1.10.3"]
[org.clojure/clojurescript "1.10.758"]]
:plugins [[lein-cljsbuild "1.1.8"]]
:cljsbuild {:builds [{:source-paths ["src"]}]})
#EDIT I had to reboot the machine then tried again by chance - it works now. but "why" remains mysterious.

Answer 1

In the tutorial, it wants src/hello_world/core.cljs as the file and hello-world.core for the namespace but you have helloworld.core for the ns and say you have src/helloworld/core.cljs for the file (which ought to work). That's the only difference I can see from the tutorial.
In addition, the tutorial has --repl on the clj command to cause a (ClojureScript) REPL to be started after compiling helloworld.core (using your ns).
That all works as expected for me:
(! 600)-> tree .
.
|____deps.edn
|____src
| |____helloworld
| | |____core.cljs
(! 601)-> cat deps.edn
{:deps {org.clojure/clojurescript {:mvn/version "1.10.758"}}}
(! 602)-> cat src/helloworld/core.cljs
(ns helloworld.core)
(println "helloworld")
(! 603)-> clj -M -m cljs.main -c helloworld.core -r
ClojureScript 1.10.758
cljs.user=> helloworld
(and a browser opens with the ClojureScript welcome page)
That was with Clojure CLI 1.10.3.1029 (the latest) but I also tested it with 1.10.1.561 to make sure recent changes haven't affected the behavior and it also worked as expected.
I would recommend checking that you have the correct Clojure CLI installed:
(! 605)-> clj -version
Clojure CLI version 1.10.3.1029
(! 606)-> clj -Sdescribe
{:version "1.10.3.1029"
:config-files ["/usr/local/Cellar/clojure#1.10.3.1029/1.10.3.1029/deps.edn" "/Users/sean/.clojure/deps.edn" "deps.edn" ]
:config-user "/Users/sean/.clojure/deps.edn"
:config-project "deps.edn"
:install-dir "/usr/local/Cellar/clojure#1.10.3.1029/1.10.3.1029"
:config-dir "/Users/sean/.clojure"
:cache-dir ".cpcache"
:force false
:repro false
:main-aliases ""
:repl-aliases ""}
(the installation instructions are here: https://clojure.org/guides/getting_started if have some rogue clj script instead of the official one)
I suspect you have a non-standard clj script installed that tried to just run helloworld.core as if it were a .clj file.