Merge branch 'main' into transformers-v5

src/chronos/base.py

@@ -348,9 +348,16 @@ class BaseChronosPipeline(metaclass=PipelineRegistry):
         if str(pretrained_model_name_or_path).startswith("s3://"):
             from .boto_utils import cache_model_from_s3
 
-            local_model_path = cache_model_from_s3(
-                str(pretrained_model_name_or_path), force_download=force_s3_download
-            )
+            try:
+                local_model_path = cache_model_from_s3(
+                    str(pretrained_model_name_or_path), force_download=force_s3_download
+                )
+            except ImportError as e:
+                raise ImportError(
+                    "Loading models from s3:// URIs requires boto3. "
+                    "Install the optional dependencies with: "
+                    "pip install 'chronos-forecasting[extras]'"
+                ) from e
             return cls.from_pretrained(local_model_path, *model_args, **kwargs)
 
         from transformers import AutoConfig

src/chronos/boto_utils.py

@@ -3,17 +3,19 @@
 
 # Authors: Abdul Fatir Ansari <ansarnd@amazon.com>
 
+from __future__ import annotations
+
 import logging
 import os
 import re
 import warnings
 from pathlib import Path
+from typing import TYPE_CHECKING
 
-import boto3
 import requests  # type: ignore
-from botocore import UNSIGNED
-from botocore.client import Config
-from botocore.exceptions import ClientError, NoCredentialsError
+
+if TYPE_CHECKING:
+    import boto3
 
 logger = logging.getLogger(__name__)
 
@@ -57,6 +59,11 @@ def download_model_files_from_s3(
     force_download: bool = False,
     boto3_session: boto3.Session | None = None,
 ) -> None:
+    import boto3
+    from botocore import UNSIGNED
+    from botocore.client import Config
+    from botocore.exceptions import ClientError, NoCredentialsError
+
     boto3_session = boto3_session or boto3.Session()
     s3_client = boto3_session.client("s3")
 
@@ -101,7 +108,7 @@ def cache_model_from_s3(
     boto3_session: boto3.Session | None = None,
 ):
     assert re.match("^s3://([^/]+)/(.*?([^/]+)/?)$", s3_uri) is not None, f"Not a valid S3 URI: {s3_uri}"
-    cache_home = Path(os.environ.get("XGD_CACHE_HOME", os.path.expanduser("~/.cache")))
+    cache_home = Path(os.environ.get("XDG_CACHE_HOME", os.path.expanduser("~/.cache")))
     cache_dir = cache_home / "chronos"
     s3_uri = s3_uri.rstrip("/")
     bucket, prefix = s3_uri.replace("s3://", "").split("/", 1)