fix: debug stuck process by sending SIGUSR1

It will print stack to stderr.

frappe/__init__.py

@@ -11,6 +11,7 @@ be used to build database driven apps.
 Read the documentation: https://frappeframework.com/docs
 """
 import copy
+import faulthandler
 import functools
 import gc
 import importlib
@@ -18,6 +19,7 @@ import inspect
 import json
 import os
 import re
+import signal
 import traceback
 import warnings
 from collections.abc import Callable
@@ -304,6 +306,7 @@ def init(site: str, sites_path: str = ".", new_site: bool = False, force=False)
 	if not _qb_patched.get(local.conf.db_type):
 		patch_query_execute()
 		patch_query_aggregation()
+		_register_fault_handler()
 
 	setup_module_map(include_all_apps=not (frappe.request or frappe.job or frappe.flags.in_migrate))
 
@@ -2542,6 +2545,10 @@ def validate_and_sanitize_search_inputs(fn):
 	return wrapper
 
 
+def _register_fault_handler():
+	faulthandler.register(signal.SIGUSR1)
+
+
 from frappe.utils.error import log_error
 
 if _tune_gc: