Warn user when plugin dependencies don't match

required minimal version

core/src/main/java/hudson/PluginWrapper.java

@@ -479,19 +479,33 @@ public class PluginWrapper implements Comparable<PluginWrapper>, ModelObject {
      */
     /*package*/ void resolvePluginDependencies() throws IOException {
         List<String> missingDependencies = new ArrayList<String>();
+        List<String> incompatibleDependencies = new ArrayList<String>();
         // make sure dependencies exist
         for (Dependency d : dependencies) {
-            if (parent.getPlugin(d.shortName) == null)
+            PluginWrapper plugin = parent.getPlugin(d.shortName);
+            if (plugin == null || plugin.isActive()) {
                 missingDependencies.add(d.toString());
+            } else if (new VersionNumber(plugin.getVersion()).isOlderThan(new VersionNumber(d.version))) {
+                incompatibleDependencies.add(d.toString());
+            }
         }
-        if (!missingDependencies.isEmpty())
-            throw new IOException("Dependency "+Util.join(missingDependencies, ", ")+" doesn't exist");
 
         // add the optional dependencies that exists
         for (Dependency d : optionalDependencies) {
-            if (parent.getPlugin(d.shortName) != null)
+            PluginWrapper plugin = parent.getPlugin(d.shortName);
+            if (plugin != null) {
                 dependencies.add(d);
+            } else if (new VersionNumber(plugin.getVersion()).isOlderThan(new VersionNumber(d.version))) {
+                incompatibleDependencies.add(d.toString());
+            }
         }
+
+        if (!missingDependencies.isEmpty())
+            throw new IOException("Dependency "+Util.join(missingDependencies, ", ")+" doesn't exist");
+
+        if (!incompatibleDependencies.isEmpty())
+            throw new IOException("Dependency "+Util.join(incompatibleDependencies, ", ")+" doesn't match required version");
+
     }
 
     /**