Example of producing multiple jars with boot

build.boot

(set-env! :source-paths #{"src"})

(def +filesets+ (atom ()))

(deftask push-fs []
  (fn [next]
    (fn [fs]
      (swap! +filesets+ conj fs)
      (next fs))))

(deftask pop-fs []
  (fn [next]
    (fn [fs]
      (if-let [prev (peek @+filesets+)]
        (do (swap! +filesets+ pop)
            (next prev))
        (next fs)))))

(deftask build []
  (comp (javac)
        (uber)
        (push-fs)
        (jar :file "main1.jar" :main 'com.example.multijar.Main1)
        (sift :include [#"^main1.jar$"])
        (target)
        (pop-fs)
        (sift :to-resource [#".*"])
        (jar :file "main2.jar" :main 'com.example.multijar.Main2)
        (sift :include [#"^main2.jar$"])
        (target :no-clean true)))