Trouble starting REPL on ubuntu 18.04

[BenLeadbetter]

I'm having trouble starting lein repl with a fresh install on ubuntu 18.04.

Disclaimer: This is my first "Hello, world!" clojure project, so I'm probably missing something obvious. Any help is much appreciated! :-)

Here are some steps to get to my issue:

1. Install the openjdk sudo apt install openjdk-8-jdk

2. Install latest lein

   • copy this file to /usr/local/bin/lein
   • sudo chmod +x /usr/local/bin/lein

3. create this minimal project file in a clean dir

   (defproject overtone-tutorial "1.0.0"
   :dependencies [[overtone/overtone "0.10.3"]]
   :native-path "native"
   :source-paths ["src"])

4. run lein repl

   • a bunch of dependencies are retreived
   • I see the following status print to the std out nREPL server started on port 37073 on host 127.0.0.1 - nrepl://127.0.0.1:37073, but I do not get any more output, or a user=> prompt. The session just hangs until I terminate it.

Am I missing something?? Thanks in advance!

[winks]

Hi, while it's probably not helpful this doesn't look like a general problem and I just tried to repro (I do have a different jdk package installed though) and can't (see below).

Can you maybe retry on another machine or via:

docker run --rm -it ubuntu:18.04 /bin/bash

λ(florian@nihil ~/tmp) $ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.6 LTS
Release:        18.04
Codename:       bionic
λ(florian@nihil ~) $ uname -a
Linux nihil 5.4.0-65-generic #73~18.04.1-Ubuntu SMP Tue Jan 19 09:02:24 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
λ(florian@nihil ~) $ dpkg -l |grep jdk
ii  openjdk-11-jdk:amd64                   11.0.14+9-0ubuntu2~18.04                        amd64        OpenJDK Development Kit (JDK)
ii  openjdk-11-jdk-headless:amd64          11.0.14+9-0ubuntu2~18.04                        amd64        OpenJDK Development Kit (JDK) (headless)
ii  openjdk-11-jre:amd64                   11.0.14+9-0ubuntu2~18.04                        amd64        OpenJDK Java runtime, using Hotspot JIT
ii  openjdk-11-jre-headless:amd64          11.0.14+9-0ubuntu2~18.04                        amd64        OpenJDK Java runtime, using Hotspot JIT (headless)
ii  openjdk-8-jdk-headless:amd64           8u312-b07-0ubuntu1~18.04                        amd64        OpenJDK Development Kit (JDK) (headless)
ii  openjdk-8-jre-headless:amd64           8u312-b07-0ubuntu1~18.04                        amd64        OpenJDK Java runtime, using Hotspot JIT (headless)
λ(florian@nihil ~) $ cd tmp
λ(florian@nihil ~/tmp) $ wget https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/lein
--2022-03-23 16:50:50--  https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/lein
Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 185.199.111.133, 185.199.108.133, 185.199.109.133, ...
Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|185.199.111.133|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 13544 (13K) [text/plain]
Saving to: ‘lein’

lein                                                        100%[========================...=====>]  13,23K  --.-KB/s    in 0,001s

2022-03-23 16:50:50 (10,6 MB/s) - ‘lein’ saved [13544/13544]

λ(florian@nihil ~/tmp) $ chmod +x lein
λ(florian@nihil ~/tmp) $ vi project.clj

# I cut out the original run here because I didn't have DEBUG and used Java 11...

λ(florian@nihil ~/tmp) $ /usr/lib/jvm/java-8-openjdk-amd64/bin/java -version                                                                                                                                                          
openjdk version "1.8.0_312"
OpenJDK Runtime Environment (build 1.8.0_312-8u312-b07-0ubuntu1~18.04-b07)
OpenJDK 64-Bit Server VM (build 25.312-b07, mixed mode)
λ(florian@nihil ~/tmp) $ JAVA_CMD=/usr/lib/jvm/java-8-openjdk-amd64/bin/java DEBUG=1 ./lein repl
Leiningen's classpath: /home/florian/.lein/self-installs/leiningen-2.9.8-standalone.jar
Applying task repl to []
Applying task javac to nil
Running javac with [@/tmp/.leiningen-cmdline1470219929842258305.tmp]
Applying task compile to nil
All namespaces already AOT compiled.
nREPL server started on port 40699 on host 127.0.0.1 - nrepl://127.0.0.1:40699
REPL-y 0.5.1, nREPL 0.8.3
Clojure 1.9.0-alpha17
OpenJDK 64-Bit Server VM 1.8.0_312-8u312-b07-0ubuntu1~18.04-b07
    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

user=>

[BenLeadbetter]

Hey! Thanks for having a look.

Hmm .. I can confirm that when I ran my repro steps in a docker container with the ubuntu 18.04 image it all ran fine - no hanging :-/.

Any ideas on what I could try to help me debug this hang on my machine?

[technomancy]

What happens if you remove the overtone dependency? Are you able to launch a repl in other projects? What about outside a project?

[BenLeadbetter]

Ok, so I've downloaded the clojure command line tools and I can successfully start a REPL with the command.

> clj

I've never started a REPL via lein on any other project file, so I don't know if the issue is particular to this project. Regarding removing the overtone dependency, I naively deleted the dependencies line from project file in my original post, but it looks like it doesn't parse correctly. This is the error I get:

> lein repl
Error: Could not find or load main class clojure.main
Subprocess failed (exit code: 1)

Could you suggest a minimal project file, without dependencies, for me to try?

[technomancy]

You can create a minimal project with lein new whatever.

[BenLeadbetter]

So, I create a blank project with lein new test_project; I run > lein repl from the project root and I get the same hanging behaviour:

nREPL server started on port 39721 on host 127.0.0.1 - nrepl://127.0.0.1:39721

and it hangs there. Never get a prompt.

[technomancy]

Hm; well without a way to reproduce the problem I don't think I can give much advice about how to fix it, but there is a workaround; you could try lein trampoline repl which will bypass nrepl and just do a fully in-process repl. You won't be able to connect your editor to it, but if the problem has something to do with the port, you could possibly work around it.

[BenLeadbetter]

Interestingly > lein trampoline repl hangs straight away. I get no output at all after running this command in a fresh project.

[technomancy]

If we can get some more details here on how to reproduce the problem we can reopen this issue, but in its present state it is not actionable.