Cache value for modinfo_path

plugins/hosts/linux/cap/nfs.rb

@@ -262,16 +262,25 @@ module VagrantPlugins
         end
 
         def self.modinfo_path
-          path = Vagrant::Util::Which.which("modinfo")
-          return path if path
+          if !defined?(@_modinfo_path)
+            @_modinfo_path = Vagrant::Util::Which.which("modinfo")
 
-          folders = ["/sbin"]
-          folders.each do |folder|
-            path = "#{folder}/modinfo"
-            return path if File.file?(path)
+            if @_modinfo_path.to_s.empty?
+              folders = ["/sbin"]
+              folders.each do |folder|
+                path = "#{folder}/modinfo"
+                if File.file?(path)
+                  @_modinfo_path = path
+                  break
+                end
+              end
+            end
+
+            if @_modinfo_path.to_s.empty?
+              @_modinfo_path = "modinfo"
+            end
           end
-
-          "modinfo"
+          @_modinfo_path
         end
 
         # @private

test/unit/plugins/hosts/linux/cap/nfs_test.rb

@@ -372,5 +372,15 @@ EOH
         expect(cap.modinfo_path).to eq("modinfo")
       end
     end
+
+    context "with cached value for modinfo_path" do
+      before do
+        cap.instance_variable_set(:@_modinfo_path, "/usr/local/bin/modinfo")
+      end
+
+      it "should use cached value" do
+        expect(cap.modinfo_path).to eq("/usr/local/bin/modinfo")
+      end
+    end
   end
 end