Graalvm version: graalvm-ce-19.0.0
Clojure version: Clojure 1.10.0
Leiningen 2.9.0 on Java 11.0.2 OpenJDK 64-Bit Server VM
In my project (https://github.com/slifin/beeline) if I run
lein run "{\":select\" [\":b\"]}"
I get
["SELECT b"]
as I expected but if I do
lein native-image
and run
./beeline-0.1.0-SNAPSHOT "{\":select\" [\":b\"]}"
I get no output, though I know my program is running because if I change the input I get errors that make sense for my program, what's stopping it from printing?
Try (flush) at the end of your main function.
Related
Recently, I started learning Clojure. I have been using Emacs, and cider (REPL). Also, I have NixOS as OS.
I have been able to successfully program in Clojure using this environment. Usually, I create the files, then I go to the directory where the .clj are, I execute cider-jack-in, a REPL is created, and interactive programming magic happens. Thus, I am able to load the file, load new versions of old functions, etc.
It also works if I just start Emacs and execute `cider-jack-in. The mini-buffer asks:
Are you sure you want to run `cider-jack-in' without a Clojure project? (y or n)
After answering y, everything works fine.
While reading the book Clojure for the Brave and True, I have also successfully used:
$ lein run
For learning purposes, I decided to explore some open source projects. Thus, I did a git clone of this open-source project.
Being on the folder, I decided to reproduce the steps that have worked so far. However, it does not work. After executing cider-jack-in, the mini-buffer echoes the following:
The clojure executable isn’t on your ‘exec-path
Also, if I try with lein I get:
[pedro#system:~/projects/http-cron]$ lein run
No :main namespace specified in project.clj.
Obs.: If I type clojure on the shell, this is what I get:
[pedro#system:~]$ clojure
The program 'clojure' is not in your PATH. You can make it available in an
ephemeral shell by typing:
nix-shell -p clojure
Why is this happening?
How can I solve this (considering that I am using NixOS)?
Going the imperative route, depending on whether you use NixOS with channels (default) or flakes, you can permanently install clojure into your environment with:
channels: nix-env -f '<nixpkgs>' -iA clojure
flakes: nix profile install nixpkgs#clojure
The preferred (declarative) way would however be adding clojure to environment.systemPackages in /etc/nixos/configuration.nix and running sudo nixos-rebuild switch.
before I start, you probably need to know three things:
I don't have Java background
I'm a Clojure newbie - started to learn it
question is related to my "training" package kennyfy
TL;DR version I'm not able to import/use my training package in a project
Longer version
I set myself a goal - write simple API which converts text to kennyspeak. Before that I've created a package (using default lein template).
I tried to import this package to my API.
Part of project.clj looks like this:
:repositories [["jitpack" "https://jitpack.io"]]
:dependencies [[com.github.radmen/clojure-kennyfy "0.1.2"]]
lein deps fetches the package without any problems.
When I try to use it, Clojure fails with following message:
kennyfy-api.core=> (radmen.kennyfy/kenny-speak "foo")
ClassNotFoundException radmen.kennyfy java.net.URLClassLoader.findClass (URLClassLoader.java:382)
I understand the error, yet I've no idea why this class is not imported.
I am quite sure, that this may be related to the metadata stored in the package, which results in failed imports.
What am I doing wrong?
Thank you
$ java -version
openjdk version "1.8.0_192"
OpenJDK Runtime Environment (build 1.8.0_192-b26)
OpenJDK 64-Bit Server VM (build 25.192-b26, mixed mode)
$ lein version
Leiningen 2.8.3 on Java 1.8.0_192 OpenJDK 64-Bit Server VM
Clojure 1.9.0
A clojure namespaces is loaded the first time it is required.
foo.core=> (radmen.kennyfy/kenny-speak "foo")
Execution error (ClassNotFoundException) at java.net.URLClassLoader/findClass (URLClassLoader.java:382).
radmen.kennyfy
foo.core=> (require '[radmen.kennyfy :as kennyfy])
nil
foo.core=> (kennyfy/kenny-speak "foo")
"mpfppfppf"
foo.core=> (radmen.kennyfy/kenny-speak "foo")
"mpfppfppf"
foo.core=>
See an error message: error in process sentinel: Could not start nREPL server: That’s not a task. Use "lein help" to list all tasks.
In the *Messages* buffer, the full form of the error is:
error in process sentinel: nrepl-server-sentinel: Could not start nREPL server: That’s not a task. Use "lein help" to list all tasks.
M-x cider-version shows
CIDER 0.15.0snapshot (package: 20170525.255)
Tried fiddling around with ~/.lein/profiles.clj to explicitly add in
{:user {:plugins [[cider/cider-nrepl "0.15.0snapshot"]]}}`
... but that didn't change anything.
(getting back to Clojure after a while with a "fresh" install (Emacs, clojure-mode, cider, etc. so might have missed some small environment setup step, just don't know what that is!)
Turns out the incompatibility was not with the nRepl middleware, but with Leiningen itself.
Once I uninstalled the version I had installed using apt-get, and self-installed using the downloaded script, and made sure this new version was what which lein led to, this problem went away.
More details: Running cider-jack-in was triggering a call to lein update-in with further arguments, but the version of Leiningen I had simply didn't show update-in as one of the options when I ran lein help.
In my Windows 7 (64 bits) environment, I have quite a few JVM available:
C:\Program Files (x86)\Java\j2re1.4.2_12\bin\client\jvm.dll
C:\Program Files (x86)\Java\jre6\bin\client\jvm.dll
D:\programs\Java\jdk1.7.0_45\jre\bin\server\jvm.dll
D:\programs\Java\jre7\bin\server\jvm.dll
Currently, with Lighttable/Leiningen (I don't know which makes the choice, and how), it uses
C:\Program Files (x86)\Java\j2re1.4.2_12\bin\client\jvm.dll
But I really would like to try
D:\programs\Java\jdk1.7.0_45\jre\bin\server\jvm.dll
It's even more puzzling that when I type
java -version
I got the following:
D:\yushen>java -version
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)
It seems that's what I want to have inside Lighttable/Leinengen.
Could you show me how to make the explicit choice/configuration?
I tried Google, but couldn't find some leads.
Thanks a lot!
I found a Leiningen profile in
$HOME/.lein/profiles.clj
For me on Windows, $HOME was D:\Users\carl . More generally, it's the directory Windows will (usually) dump you in if you start the shell using CMD .
This contained:
{:user
{
:java-cmd "F:\\JDK8\\bin\\java.exe"
:plugins [
]
}
}
...which I was able to change to good effect.
Put the JDK's bin directory in your path first. It's the surest way.
More detail. Windows, you can use the where command to see what version of an executable. It's either where java or where java.exe You can also look at your path from the command prompt by typing path. If you're launching something from the command line, and it's not undertaking strange measures to find the JVM, it should come up with the first one in your path, which should agree with the results of running the where command.
If the where command is coming up with something you don't expect, either add the right directory to your path before the entry that's coming up or rearrange your path so it's coming up first.
To test this in leiningen, start a repl, and evaluate this.
(println (System/getProperty "java.version"))
e.g.
Yoyo-2:Desktop bill$ lein repl
(System/getPnREPL server started on port 61475 on host 127.0.0.1 - nrepl://127.0.0.1:61475
REPL-y 0.3.5, nREPL 0.2.6
Clojure 1.6.0
Java HotSpot(TM) 64-Bit Server VM 1.8.0_20-b26
Docs: (doc function-name-here)
(find-doc "part-of-name-here")
Source: (source function-name-here)
Javadoc: (javadoc java-object-or-class-here)
Exit: Control+D or (exit) or (quit)
Results: Stored in vars *1, *2, *3, an exception in *e
ruser=> (System/getProperty "java.version")
"1.8.0_20"
In my experience, Leiningen has always used the version of java it finds in the path. No experience with light table though.
For Leiningen, you can edit lein.bat to point exactly to your desired Java SDK version. I don't know if the same could apply to LightTable.
Or you can set a global JAVA_HOME. That is really Googleable (or DuckDuckGo-able).
Finally, I found this link: http://leiningen-win-installer.djpowell.net/
After running the installer, it has the function to re-configure leiningen, using it, I was able to configure my old leiningen to use my desired JDK: D:\programs\Java\jdk1.7.0_45\bin\java.exe, then the JVM instance in leiningen/lighttable is the desired one now.
The moral of the story: leiningen needs to be reconfigured with newly installed JDK with the configuration functionality of leiningen-win-installer.
It might be possible to configure leiningen manually, but I hadn't found a way to do yet.
I tried to manually configure through my project.clj with java-command option, it didn't work.
In clojure I can run:
lein run -m my.namespace # run the -main function of a namespace
and this will run my code from the command line.
Is there an equivalent for Clojurescipt to run the generated code in node.js? (In leiningen)
(I have read the doco for starting the Clojurescript REPL, for the running on node.js and the reply integrated into my application. I was just looking for a one-line command line solution.)
Depending on what your goal is, you might find it useful to use 'cljsbuild test'. You can specify a test context on your project.clj that uses node.js/v8/phantomjs.
Example:
:cljsbuild {
:test-commands {
"v8" ["v8"
"target/generated-sources/private/js/client.js"
"tests/v8-test-runner.js"]}}
v8-test-runner.js:
path.to.your.entrypoint.start()
You can also leave 'lein cljsbuild auto' running and start the javascript application directly:
v8 target/generated-sources/private/js/client.js tests/v8-test-wrapper.js
That's probably the best option if you are building a node.js application using clojurescript. You don't need to worry about classpaths in javascript (which is the major thing that lein run provides), you can just run your application directly from the assembled javascript file.