Fix Custom Excepthook

NextGen_Forcings_Engine_BMI/NextGen_Forcings_Engine/core/err_handler.py

@@ -3,6 +3,7 @@
 import os
 import sys
 import traceback
+import typing
 
 import numpy as np
 from mpi4py import MPI
@@ -19,6 +20,13 @@ def in_exception_context() -> bool:
     return False
 
 
+def cast_err_msg_to_str(err_msg: str | typing.Any):
+    """If err_msg is not a string, cast it to string and add a note flagging the type provided."""
+    if not isinstance(err_msg, str):
+        err_msg = f"Expected instance of str for err_msg, got type: {type(err_msg)}: {err_msg}"
+    return err_msg
+
+
 def err_out_screen(err_msg: str, exc: BaseException | None = None):
     """Print an error message to the screen and exit the program gracefully.
 
@@ -31,6 +39,7 @@ def err_out_screen(err_msg: str, exc: BaseException | None = None):
 
     Logan Karsten - National Center for Atmospheric Research, karsten@ucar.edu
     """
+    err_msg = cast_err_msg_to_str(err_msg)
     if exc is not None:
         err_msg += f" - {exc}"
     err_msg_out = "ERROR: " + err_msg
@@ -65,6 +74,7 @@ def err_out_screen_para(err_msg: str, MpiConfig, exc: BaseException | None = Non
     :param exc: Optional exception object to append to the error message.
     :return: None
     """
+    err_msg = cast_err_msg_to_str(err_msg)
     if exc is not None:
         err_msg += f" - {exc}"
     err_msg_out = f"ERROR: RANK - {MpiConfig.rank} : {err_msg}"

NextGen_Forcings_Engine_BMI/NextGen_Forcings_Engine/core/parallel.py

@@ -46,6 +46,8 @@ def __init__(self, config_options: ConfigOptions):
         self.log_debug = partial(err_handler.log_msg, self.config_options, self, True)
         self.log_info = partial(err_handler.log_msg, self.config_options, self, False)
         self.log_warning = partial(err_handler.log_warning, self.config_options, self)
+
+        self.original_excepthook = None  # Will be set to the original sys.excepthook when __register_exit_handlers is called
         self.__register_exit_handlers()
 
     def initialize_comm(self, comm=None):
@@ -145,7 +147,8 @@ def __register_exit_handlers(self) -> None:
         against potential deadlock conditions to be sure (would need to confirm that a non-0 rank initiating an abort would cause
         rank 0 break out of a collective call if it happens to be waiting at one)."""
         # Exceptions
-        sys.exepthook = self.__excepthook
+        self.original_excepthook = sys.excepthook
+        sys.excepthook = self.__excepthook
         # Regular exits
         atexit.register(self._cleanup)
         # Signals
@@ -154,13 +157,23 @@ def __register_exit_handlers(self) -> None:
 
     def __excepthook(self, ex_type, value, tb) -> None:
         """Custom excepthook which follows these steps:
-        1. Call Python's built-in excepthook.
+        1. Call original excepthook which had been saved earlier.
         2. Log .errMsg as CRITICAL (unless it is None).
         3. Cleanup.
         4. MPI Abort.
 
-        To apply, set `sys.excepthook` to this method."""
-        sys.__excepthook__(ex_type, value, tb)
+        To apply:
+            Set `self.original_excepthook = sys.excepthook`,
+            Then set `sys.excepthook = {this method}`.
+        """
+        # Call original excepthook stored earlier (not raw sys.__excepthook__)
+        if self.original_excepthook is None:
+            raise RuntimeError(
+                "In custom __excepthook, but self.original_excepthook does not contain the saved original hook as expected."
+            )
+        self.original_excepthook(ex_type, value, tb)
+
+        # Perform additional actions
         if self.config_options.errMsg is not None:
             err_handler.log_critical(
                 self.config_options,