index_build: Clear existing /indexes if it exists.

To enable re-indexing on a container that already had indexing done previously.
Otherwise we might run into issues (e.g. indexer complaining files already exist).

PiperOrigin-RevId: 780042087

Author: OSS-Fuzz Team

infra/base-images/base-builder/indexer/index_build.py

@@ -553,7 +553,6 @@ def clear_out():
 
 def main():
   logging.basicConfig(level=logging.INFO)
-  INDEXES_PATH.mkdir(exist_ok=True)
 
   parser = argparse.ArgumentParser(description='Index builder.')
   parser.add_argument(
@@ -617,6 +616,11 @@ def main():
   )
   args = parser.parse_args()
 
+  # Clear existing indexer artifacts.
+  if INDEXES_PATH.exists():
+    shutil.rmtree(INDEXES_PATH)
+  INDEXES_PATH.mkdir()
+
   # Clean up the existing OUT by default, otherwise we may run into various
   # build errors.
   if not args.no_clear_out: