refactor musl tool doctor

src/SPC/store/Downloader.php

@@ -261,10 +261,13 @@ class Downloader
 
         if ($source === null) {
             logger()->warning('Source {name} unknown. Skipping.', ['name' => $name]);
-
             return;
         }
 
+        if (!is_dir(DOWNLOAD_PATH)) {
+            FileSystem::createDir(DOWNLOAD_PATH);
+        }
+
         // load lock file
         if (!file_exists(DOWNLOAD_PATH . '/.lock.json')) {
             $lock = [];