[CI] add polling for precompiled wheel in python_only_compile.sh, fix index generation for releases (#30781)

Signed-off-by: Shengqi Chen <harry-chen@outlook.com>

.buildkite/scripts/generate-nightly-index.py

@@ -291,6 +291,7 @@ if __name__ == "__main__":
     """
     Arguments:
         --version <version> : version string for the current build (e.g., commit hash)
+        --wheel-dir <wheel_directory> : directory containing wheel files (default to be same as `version`)
         --current-objects <path_to_json> : path to JSON file containing current S3 objects listing in this version directory
         --output-dir <output_directory> : directory to store generated index files
         --alias-to-default <alias_variant_name> : (optional) alias variant name for the default variant
@@ -318,6 +319,12 @@ if __name__ == "__main__":
         required=True,
         help="Directory to store generated index files",
     )
+    parser.add_argument(
+        "--wheel-dir",
+        type=str,
+        default=None,
+        help="Directory containing wheel files (default to be same as `version`)",
+    )
     parser.add_argument(
         "--alias-to-default",
         type=str,
@@ -384,9 +391,10 @@ if __name__ == "__main__":
         print("Nightly version detected, keeping all wheel files.")
 
     # Generate index and metadata, assuming wheels and indices are stored as:
-    # s3://vllm-wheels/{version}/<wheel files>
+    # s3://vllm-wheels/{wheel_dir}/<wheel files>
     # s3://vllm-wheels/<anything>/<index files>
-    wheel_base_dir = Path(output_dir).parent / version
+    wheel_dir = args.wheel_dir or version
+    wheel_base_dir = Path(output_dir).parent / wheel_dir.strip().rstrip("/")
     index_base_dir = Path(output_dir)
 
     generate_index_and_metadata(