Better error message when signal is not supported on OS (#25049)

* Better error message when signal is not supported on OS

* Address review comments

src/transformers/dynamic_module_utils.py

@@ -532,6 +532,7 @@ def resolve_trust_remote_code(trust_remote_code, model_name, has_local_code, has
         if has_local_code:
             trust_remote_code = False
         elif has_remote_code and TIME_OUT_REMOTE_CODE > 0:
+            try:
                 signal.signal(signal.SIGALRM, _raise_timeout_error)
                 signal.alarm(TIME_OUT_REMOTE_CODE)
                 while trust_remote_code is None:
@@ -545,6 +546,13 @@ def resolve_trust_remote_code(trust_remote_code, model_name, has_local_code, has
                     elif answer.lower() in ["no", "n", "0", ""]:
                         trust_remote_code = False
                 signal.alarm(0)
+            except AttributeError:
+                # OS which does not support signal.SIGALRM
+                raise ValueError(
+                    "Loading this model requires you to execute execute some code in that repo on your local machine. "
+                    f"Make sure you have read the code at https://hf.co/{model_name} to avoid malicious use, then set "
+                    "the option `trust_remote_code=True` to remove this error."
+                )
         elif has_remote_code:
             # For the CI which puts the timeout at 0
             _raise_timeout_error(None, None)