BUG: Solved problems that happened in unit test "VagrantPlugins::HyperV::Action::Configure", "should call the app on success". The problems occured because controllers was being called when it wasn't defined. Solved by implementing if test for this.

plugins/providers/hyperv/action/import.rb

@@ -17,7 +17,7 @@ module VagrantPlugins
         def call(env)
           vm_dir = env[:machine].box.directory.join("Virtual Machines")
           hd_dir = env[:machine].box.directory.join("Virtual Hard Disks")
-          controllers = env[:machine].provider_config.controllers
+
           if !vm_dir.directory? || !hd_dir.directory?
             @logger.error("Required virtual machine directory not found!")
             raise Errors::BoxInvalid, name: env[:machine].name
@@ -61,6 +61,8 @@ module VagrantPlugins
           env[:ui].output("Importing a Hyper-V instance")
           dest_path = env[:machine].data_dir.join("Virtual Hard Disks").join(image_path.basename).to_s
 
+          if defined? env[:machine].provider_config.controllers
+            controllers = env[:machine].provider_config.controllers
             disks_to_create = []
             data_dir = env[:machine].data_dir
             # This can happen when creating new on up.
@@ -89,6 +91,7 @@ module VagrantPlugins
               }
             }
             disks_to_create_json = disks_to_create.to_json.to_s.gsub('"', '"""')
+          end
 
           options = {
             "VMConfigFile" => Vagrant::Util::Platform.wsl_to_windows_path(config_path).gsub("/", "\\"),