Replace raise by warning to unblock unrecognized torchao version (#3338)

Add is_fbcode() check to unblock unrecognized torchao version (#3338)

Summary:

As title.

Differential Revision: D87008228

Co-authored-by: Kai Li <[email protected]>

Author: KaiserLeave

torchao/__init__.py

@@ -26,6 +26,10 @@
 logger = logging.getLogger(__name__)
 
 
+def is_fbcode():
+    return not hasattr(torch.version, "git_version")
+
+
 def _parse_version(version_string):
     """
     Parse version string representing pre-release with -1
@@ -48,7 +52,7 @@ def _parse_version(version_string):
 force_skip_loading_so_files = (
     os.getenv("TORCHAO_FORCE_SKIP_LOADING_SO_FILES", "0") == "1"
 )
-if force_skip_loading_so_files:
+if force_skip_loading_so_files or is_fbcode():
     # user override
     # users can set env var TORCHAO_FORCE_SKIP_LOADING_SO_FILES=1 to skip loading .so files
     # this way, if they are using an incompatbile torch version, they can still use the API by setting the env var