Getting Runtime Access to Clojure version number - jar

Question

From this so question I developed the code below. For now its only purpose (compiled as an uberjar) is to print its version number and exit.
; core.clj
(ns clojure-test-vnum.core
(:gen-class))
(defn implementation-version []
(-> (eval 'clojure-test-vnum.core) .getPackage .getImplementationVersion))
(defn -main
"I don't do a whole lot ... yet."
[& args]
;; work around dangerous default behaviour in Clojure
(alter-var-root #'*read-eval* (constantly false))
(println (implementation-version)))
;project.clj
(def version "0.1.0-SNAPSHOT")
(defproject clojure-test-vnum version
:manifest {"Implementation-Version" ~version}
:description "Test to see if I can get a version number from an uberjar."
:url "http://example.com/FIXME"
:license {:name "Eclipse Public License"
:url "http://www.eclipse.org/legal/epl-v10.html"}
:dependencies [[org.clojure/clojure "1.5.1"]]
:main clojure-test-vnum.core
:aot [clojure-test-vnum.core])
While this code compiles fine, I am getting a ClassNotFoundException at runtime. The problem seems to be with (eval 'clojure-test-vnum.core).
Following is the full stack trace:
Exception in thread "main" java.lang.ClassNotFoundException: clojure-test-vnum.core, compiling:(NO_SOURCE_PATH:0:0)
at clojure.lang.Compiler.analyze(Compiler.java:6380)
at clojure.lang.Compiler.analyze(Compiler.java:6322)
at clojure.lang.Compiler.eval(Compiler.java:6623)
at clojure.lang.Compiler.eval(Compiler.java:6582)
at clojure.core$eval.invoke(core.clj:2852)
at clojure_test_vnum.core$implementation_version.invoke(core.clj:5)
at clojure_test_vnum.core$_main.doInvoke(core.clj:14)
at clojure.lang.RestFn.invoke(RestFn.java:397)
at clojure.lang.AFn.applyToHelper(AFn.java:159)
at clojure.lang.RestFn.applyTo(RestFn.java:132)
at clojure_test_vnum.core.main(Unknown Source)
Caused by: java.lang.ClassNotFoundException: clojure-test-vnum.core
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at clojure.lang.DynamicClassLoader.findClass(DynamicClassLoader.java:61)
at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:266)
at clojure.lang.RT.classForName(RT.java:2070)
at clojure.lang.Compiler.resolveIn(Compiler.java:6855)
at clojure.lang.Compiler.resolve(Compiler.java:6818)
at clojure.lang.Compiler.analyzeSymbol(Compiler.java:6779)
at clojure.lang.Compiler.analyze(Compiler.java:6343)
... 10 more
What am I doing wrong ?

Answer 1

You'll need to change
(eval 'clojure-test-vnum.core)
to
clojure_test_vnum.core
since the generated class will have underscores in its name in place of the hyphens in the name of the Clojure entity it is based on. No eval is necessary, the symbol will simply resolve to the class.