Support :local-repo-classpath.

TODO: ant still spews out a bunch of useless output; doesn't seem to
be a way to suppress the noise.

sample.project.clj

@@ -136,6 +136,8 @@
   :extra-classpath-dirs ["script"] ; more classpath entries not included in jar
   :jar-name "sample.jar"           ; name of the jar produced by 'lein jar'
   :uberjar-name "sample-standalone.jar" ; as above for uberjar
+  ;; Construct classpath from jars in ~/.m2 rather than copying to :library-path
+  :local-repo-classpath true
   ;; Options to pass to java compiler for java source
   ;; See http://ant.apache.org/manual/Tasks/javac.html
   :javac-options {:destdir "classes/"}

src/leiningen/classpath.clj

@@ -1,15 +1,35 @@
 (ns leiningen.classpath
   "Print the classpath of the current project."
   (:use [leiningen.core :only [read-project home-dir]]
+        [leiningen.deps :only [do-deps]]
         [clojure.java.io :only [file]]
         [clojure.string :only [join]])
+  (:require [lancet.core :as lancet]
+            [clojure.string :as string])
   (:import (org.apache.tools.ant.types Path)))
 
-(defn ^:internal find-lib-jars
+(defn ^{:internal true} fileset-paths [fileset]
+  (-> fileset
+      (.getDirectoryScanner lancet/ant-project)
+      (.getIncludedFiles)))
+
+(defn- find-lib-jars [project]
+  (.listFiles (file (:library-path project))))
+
+(defn- find-local-repo-jars [project]
+  ;; TODO: Shut up, ant. You are useless. Nobody cares about what you say.
+  ;; Removing ant-project loggers and redirecting their output streams
+  ;; does nothing. How to suppress output?
+  (for [path (fileset-paths (do-deps project :dependencies))]
+    (file (System/getProperty "user.home") ".m2" "repository" path)))
+
+(defn ^:internal find-jars
   "Returns a seq of Files for all the jars in the project's library directory."
   [project]
   (filter #(.endsWith (.getName %) ".jar")
-          (concat (.listFiles (file (:library-path project)))
+          (concat (if (:local-repo-classpath project)
+                    (find-local-repo-jars project)
+                    (find-lib-jars project))
                   ;; This must be hard-coded because it's used in
                   ;; bin/lein and thus can't be changed in project.clj.
                   (.listFiles (file (:root project) "lib/dev")))))
@@ -59,7 +79,7 @@
            (:resources-path project)]
           (:extra-classpath-dirs project)
           (checkout-deps-paths project)
-          (find-lib-jars project)
+          (find-jars project)
           (user-plugins)))
 
 (defn get-classpath-string [project]

src/leiningen/compile.clj

@@ -4,7 +4,7 @@
   (:use [leiningen.deps :only [deps]]
         [leiningen.core :only [ns->path user-settings]]
         [leiningen.javac :only [javac]]
-        [leiningen.classpath :only [make-path find-lib-jars get-classpath]]
+        [leiningen.classpath :only [make-path find-jars get-classpath]]
         [clojure.java.io :only [file resource reader]]
         [leiningen.util.ns :only [namespaces-in-dir]])
   (:refer-clojure :exclude [compile])
@@ -165,7 +165,7 @@
              (empty? (.list (file (:compile-path project)))))
     (binding [*silently* true]
       (compile project)))
-  (when (or (empty? (find-lib-jars project))
+  (when (or (empty? (find-jars project))
             (:checksum-deps project))
     (deps project))
   (if (:eval-in-leiningen project)

src/leiningen/deps.clj

@@ -127,15 +127,17 @@
   (let [deps-task (make-deps-task project deps-set)]
     (when (seq (deps-set project))
       (.execute deps-task)
-      (.mkdirs (File. (:library-path project)))
-      (copy-dependencies (:jar-behavior project)
-                         ;; Leiningen's process only has access to lib/dev.
-                         (if (or (= :dev-dependencies deps-set)
-                                 (:eval-in-leiningen project))
-                           (str (:root project) "/lib/dev")
-                           (:library-path project))
-                         true (.getReference lancet/ant-project
-                                             (.getFilesetId deps-task))))
+      (when-not (or (:local-repo-classpath project)
+                    (:eval-in-leiningen project))
+        (.mkdirs (File. (:library-path project)))
+        (copy-dependencies (:jar-behavior project)
+                           ;; Leiningen's process only has access to lib/dev.
+                           (if (or (= :dev-dependencies deps-set)
+                                   (:eval-in-leiningen project))
+                             (str (:root project) "/lib/dev")
+                             (:library-path project))
+                           true (.getReference lancet/ant-project
+                                               (.getFilesetId deps-task)))))
     (.getReference lancet/ant-project (.getFilesetId deps-task))))
 
 (defn native-deps [project]