fix(python): Fix credential provider error (#21092)

py-polars/polars/io/cloud/credential_provider.py

@@ -577,20 +577,9 @@ def _maybe_init_credential_provider(
                     # Conservatively warn instead of hard error. It could just be
                     # set as a default environment flag.
                     issue_warning(msg, UserWarning)
-                # Note: Enclosing scope is also within a try-except.
+                # Note: Enclosing scope will catch ImportErrors
                 raise
 
-            # CredentialProviderAWS raises an error in some cases when
-            # `get_credentials()` returns None (e.g. the environment may not
-            # have / require credentials). We check this here and avoid
-            # auto-initializing it if that is the case.
-            try:
-                provider()
-            except Exception as e:
-                provider = None
-                msg = f"error retrieving credentials: {e}"
-                raise type(e)(msg) from e
-
         elif storage_options is not None and any(
             key.lower() not in OBJECT_STORE_CLIENT_OPTIONS for key in storage_options
         ):
@@ -600,9 +589,23 @@ def _maybe_init_credential_provider(
 
     except ImportError as e:
         if verbose:
-            msg = f"Unable to auto-select credential provider: {e}"
+            msg = f"unable to auto-select credential provider: {e!r}"
             print(msg, file=sys.stderr)
 
+    if provider is not None:
+        # CredentialProviderAWS raises an error in some cases when
+        # `get_credentials()` returns None (e.g. the environment may not
+        # have / require credentials). We check this here and avoid
+        # using it if that is the case.
+        try:
+            provider()
+        except Exception as e:
+            provider = None
+
+            if verbose:
+                msg = f"unable to auto-select credential provider: {e!r}"
+                print(msg, file=sys.stderr)
+
     if provider is not None and verbose:
         msg = f"auto-selected credential provider: {type(provider).__name__}"
         print(msg, file=sys.stderr)