Issue #3365151: CollectPathsToExcludeEvent needs to exclude paths relative to the project root prefixed with './' so they are not ambiguous to rsync

package_manager/src/Event/CollectPathsToExcludeEvent.php

@@ -106,6 +106,12 @@ final class CollectPathsToExcludeEvent extends StageEvent implements PathListInt
       // so that they're totally unambiguous. A path like
       // `/path/to/project/file.php` should become `/file.php`.
       $path = str_replace($project_root, '', $path);
+      if ($path[0] == '/') {
+        $path = '.' . $path;
+      }
+      else {
+        $path = './' . $path;
+      }
       $this->add([$path]);
     }
   }