Can't build a jar using Leiningen - clojure

Question

I'm trying to make a stand alone jar from my bare-bones Clojure project using the Leiningen plugin in Intellij's Cursive.
To create the project, I just created the project.clj file, opened it, and Cursive offered to import it as a project.
project.clj:
(defproject WaterTimer "1"
:description "A timer that reminds you to drink water"
:main tone-producer/main)
tone-producer.clj:
(ns tone-producer
(:require [general-helpers :as g])
(:import [javax.sound.midi MidiSystem
Synthesizer
MidiChannel])
(:gen-class))
(defn main [& args]
(println "Test!"))
When I run the "uberjar" task, I get the following output:
Warning: specified :main without including it in :aot.
Implicit AOT of :main will be removed in Leiningen 3.0.0.
If you only need AOT for your uberjar, consider adding :aot :all into your
:uberjar profile instead.
Warning: The Main-Class specified does not exist within the jar. It may not be executable as expected. A gen-class directive may be missing in the namespace which contains the main method.
Created C:\Users\slomi\IdeaProjects\WaterTimer\target\WaterTimer-1.jar
Created C:\Users\slomi\IdeaProjects\WaterTimer\target\WaterTimer-1-standalone.jar
I also tried changing the main function to have the default name, and omit the name from the defproject:
(defproject WaterTimer "1"
:description "A timer that reminds you to drink water"
:main tone-producer)
(ns tone-producer
(:require [general-helpers :as g])
(:import [javax.sound.midi MidiSystem
Synthesizer
MidiChannel])
(:gen-class))
(defn -main [& args]
(println "Test!"))
But now I get the error:
Error: Could not find or load main class clojure.main
Compilation failed: Subprocess failed
The structure is:
WaterTimer
src
tone-producer.clj
project.clj
target
Any guidance here would be appreciated.

Answer 1

After a bit of fiddling
I dropped (:require [general-helpers :as g]) since its not necessary to demostrate the issue
Error: Could not find or load main class clojure.main Compilation failed
you didn't include the clojure dependency [1]
:gen-class needs AOT - as Sanchayan pointed out
see [2]
project.clj
(defproject WaterTimer "0.0.1"
:description "A timer that reminds you to drink water"
:dependencies [[org.clojure/clojure "1.8.0"]] ;; <- [1]
:main tone-producer
:aot [tone-producer]) ;; <- [2]
src/tone_producer.clj - USE '_' instead of '-' in the filename
(ns tone-producer
(:import [javax.sound.midi MidiSystem
Synthesizer
MidiChannel])
(:gen-class))
(defn -main [& args]
(println "Test!"))
Result:
$ lein uberjar
Compiling tone-producer
Compiling tone-producer
Created .../watertimer/target/WaterTimer-0.0.1.jar
Created .../watertimer/target/WaterTimer-0.0.1-standalone.jar
$ java -jar target/WaterTimer-0.0.1-standalone.jar
Test!
Generally I'd recommend to init a project with lein new <name> via command line and the import it into Cursive/Other IDE of choice.

Answer 2

For creating uberjars, the project file should have the :aot keyword enabling ahead of time compilation.
Here is an output from my project.clj file.
(defproject jdbc "0.1.0-SNAPSHOT"
:description "JDBC Project"
:url "http://example.com/FIXME"
:license {:name "Eclipse Public License"
:url "http://www.eclipse.org/legal/epl-v10.html"}
:dependencies [[org.clojure/clojure "1.8.0"]
[org.clojure/java.jdbc "0.6.1"]
[postgresql "9.3-1102.jdbc41"]
[com.mchange/c3p0 "0.9.5.2"]
[byte-streams "0.2.2"]]
:main jdbc.core
:aot [jdbc.core])
Note the :main and :aot entries. Also it needs to be -main as already stated by birdspider.