Getting an exception when trying to run lein

Question

I get the following exception when trying to run lein in linux.

Exception in thread "main" java.lang.NoClassDefFoundError: clojure.core.protocols$fn__5393
   at java.lang.Class.initializeClass(libgcj.so.10)
   at clojure.core.protocols__init.load(Unknown Source:16)
   at clojure.core.protocols__init.<clinit>(Unknown Source)
   at java.lang.Class.initializeClass(libgcj.so.10)
   at java.lang.Class.forName(libgcj.so.10)
   at clojure.lang.RT.loadClassForName(RT.java:1578)
   at clojure.lang.RT.load(RT.java:399)
   at clojure.lang.RT.load(RT.java:381)
   at clojure.core$load$fn__4519.invoke(core.clj:4915)
   at clojure.core$load.doInvoke(core.clj:4914)
   at clojure.lang.RestFn.invoke(RestFn.java:408)
   at clojure.core__init.load(Unknown Source:5342)
   at clojure.core__init.<clinit>(Unknown Source)
   at java.lang.Class.initializeClass(libgcj.so.10)
   at java.lang.Class.forName(libgcj.so.10)
   at clojure.lang.RT.loadClassForName(RT.java:1578)
   at clojure.lang.RT.load(RT.java:399)
   at clojure.lang.RT.load(RT.java:381)
   at clojure.lang.RT.doInit(RT.java:416)
   at clojure.lang.RT.<clinit>(RT.java:302)
   at java.lang.Class.initializeClass(libgcj.so.10)
   at clojure.main.<clinit>(main.java:20)
   at java.lang.Class.initializeClass(libgcj.so.10)
   at java.lang.Class.forName(libgcj.so.10)
   at java.lang.Class.forName(libgcj.so.10)
   at jline.ConsoleRunner.main(ConsoleRunner.java:69)
Caused by: java.lang.VerifyError: verification failed at PC 214 in      
clojure.core.protocols$fn__5393:invoke((Ljava.lang.Object;Ljava.lang.Object;Ljava.lang.Obje    ct;)Ljava.lang.Object;): incompatible type on stack
   at java.lang.Class.initializeClass(libgcj.so.10)
   ...25 more

I've followed the instructions on their github page, but no luck. I thought it would be fun to start learning clojure today but instead I've had nothing but problems, I don't even know what leiningen is, other than I apparently have to have it.

when posting leiningen questions it helps a lot to post your project.clj file with it. — Arthur Ulfeldt
libgcj.so in the stacktrace is a horrifying red flag. gcj doesn't work, like at all, for any realistic java programs. It's very sad that some package managers prefer to install gcj instead of openjdk or oracle's jdk, but if you want to do anything with java I recommend throwing away gcj and installing openjdk. — amalloy

Arthur Ulfeldt Arthur Ulfeldt · Accepted Answer · 2012-04-24T22:39:39

sorry about the frusteration,

Leiningen is a build tool to take the pain out of getting hacking on a new clojure project. Before leiningen existed many people would try to "install" clojure by downloading a jar file out build it from source. Instead of doing any of that you just specify the version you want to use in the leiningen project.clj file and it installs it locally as a dependency for that project.

have you run:

lein new hello_clojure
cd hello_clojure
edit project.clj and set it to use clojure 1.3.0 :dependencies [[org.clojure/clojure "1.3.0"]
lein deps
lein repl
(+ 1 2 3 4)

When things go wrong with leiningen I generally:

lein upgrade
rm lib/*
lein deps

Problems like this are uncommon (for me) and usually fairly specific, so perhaps you would do well to drop into #clojure on irc.freenode.net and ask. It's a very friendly croud dont worry.

Getting an exception when trying to run lein

1 Answers