Issue #3328234: Improve test DX *and* confidence: assert VFS state

package_manager/src/Stage.php

@@ -543,6 +543,8 @@ class Stage implements LoggerAwareInterface {
     if (file_exists($staging_root)) {
       try {
         $this->fileSystem->deleteRecursive($staging_root, function (string $path): void {
+          var_dump($path);
+          var_dump(posix_getpwuid(stat($path)['uid']));
           $this->fileSystem->chmod($path, 0777);
         });
       }