Added support for :exact-lein-version.

leiningen-core/src/leiningen/core/main.clj

@@ -348,6 +348,21 @@ These get replaced with the corresponding values from the project map."
               (.load reader))
             (.getProperty "version")))))
 
+(def ^:private exact-version-error
+  "This project has :exact-lein-version set to \"%s\", while you have %s.")
+
+(defn versions-match? [v1 v2]
+  (let [v1 (string/trim (first (string/split v1 #"-" 2)))
+        v2 (string/trim (first (string/split v2 #"-" 2)))]
+    (= v1 v2)))
+
+(defn- verify-exact-version
+  [{:keys [exact-lein-version]}]
+  (when-not (versions-match? exact-lein-version (leiningen-version))
+    (abort (format exact-version-error
+                   exact-lein-version
+                   (leiningen-version)))))
+
 (defn version-satisfies? [v1 v2]
   (let [v1 (map #(Integer. %) (re-seq #"\d+" (first (string/split v1 #"-" 2))))
         v2 (map #(Integer. %) (re-seq #"\d+" (first (string/split v2 #"-" 2))))]
@@ -415,6 +430,7 @@ intentional please see `lein help faq` for details."))
     (let [project (if (.exists (io/file *cwd* "project.clj"))
                     (project/read (str (io/file *cwd* "project.clj")))
                     (default-project))]
+      (when (:exact-lein-version project) (verify-exact-version project))
       (when (:min-lein-version project) (verify-min-version project))
       (configure-http)
       (resolve-and-apply project raw-args))

leiningen-core/test/leiningen/core/test/main.clj

@@ -91,6 +91,18 @@
        ["one-or-two" "clojure" "2"] ["3"]
        ["fixed-and-var-args" "one"] []))
 
+(deftest test-versions-match
+  (is (versions-match? "1.2.12" "1.2.12"))
+  (is (versions-match? "3.0" "3.0"))
+  (is (versions-match? " 12.1.2" "12.1.2 "))
+  (is (not (versions-match? "1.2" "1.3")))
+  (is (not (versions-match? "1.2.0" "1.2")))
+  (is (not (versions-match? "1.2" "1.2.0")))
+  (is (versions-match? "2.1.3-SNAPSHOT" "2.1.3"))
+  (is (versions-match? "  2.1.3-SNAPSHOT" "2.1.3"))
+  (is (versions-match? "2.1.3" "2.1.3-FOO"))
+  (is (not (versions-match? "3.0.0" "3.0.1-BAR"))))
+
 (deftest test-version-satisfies
   (is (version-satisfies? "1.5.0" "1.4.2"))
   (is (not (version-satisfies? "1.4.2" "1.5.0")))

sample.project.clj

@@ -36,6 +36,11 @@
   ;; relies on features only found in newer Leiningen versions.
   :min-lein-version "2.0.0"
 
+  ;; You can require a specific version of Leiningen. In case of mismatch
+  ;; execution will abort. When versions are compared, suffixes such as
+  ;; "-SNAPSHOT" are dropped.
+  ;; :exact-lein-version "2.8.2"
+
 ;;; Dependencies, Plugins, and Repositories
   ;; Dependencies are listed as [group-id/name version]; in addition
   ;; to keywords supported by Pomegranate, you can use :native-prefix