From 4f05c6b9f716f61d0958931f19392648a81075b6 Mon Sep 17 00:00:00 2001
From: The MMGen Project <mmgen@tuta.io>
Date: Mon, 10 Aug 2026 09:54:40 +0000
Subject: [PATCH] devtools: print_stack_trace(): fix

---
 mmgen/devtools.py          | 9 ++++-----
 pyproject.toml             | 1 +
 test/modtest_d/devtools.py | 6 ++++--
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/mmgen/devtools.py b/mmgen/devtools.py
index 6976b394..f7a32ed7 100755
--- a/mmgen/devtools.py
+++ b/mmgen/devtools.py
@@ -53,15 +53,14 @@ def Pdie(*args, exit_val=1):
 def Pexit(*args):
 	Pdie(*args, exit_val=0)
 
-def print_stack_trace(message=None, fh_list=[], nl='\n', sep='\n  ', trim=4):
+def print_stack_trace(message=None, fh_list=[], sep='\n  ', trim=4):
+	res = get_stack_trace(message, ('\n' if fh_list else ''), sep, trim)
 	if not fh_list:
 		import os
-		with open(f'devtools.trace.{os.getpid()}', 'w') as fh:
-			fh_list.append(fh)
-		nl = ''
-	res = get_stack_trace(message, nl, sep, trim)
+		fh_list.append(open(f'devtools.trace.{os.getpid()}', 'w'))
 	sys.stderr.write(res)
 	fh_list[0].write(res)
+	fh_list[0].flush()
 
 def get_stack_trace(message=None, nl='\n', sep='\n  ', trim=3):
 
diff --git a/pyproject.toml b/pyproject.toml
index 865fa4be..58cf52d8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,6 +41,7 @@ ignore = [
 "mmgen/tool/file.py"          = [ "B008" ]     # function call in dfl args
 "mmgen/tool/rpc.py"           = [ "RUF013" ]   # PEP 484 prohibits implicit `Optional`
 "mmgen/contrib/keccak.py"     = [ "FURB163" ]  # `math.log` -> `math.log2(state.lanew)`
+"mmgen/devtools.py"           = [ "SIM115" ]   # open() with context manager
 "mmgen/proto/eth/rlp/*" = [
 	"TRY002", # create your own exception
 	"UP004",  # class `Binary` inherits from `object`
diff --git a/test/modtest_d/devtools.py b/test/modtest_d/devtools.py
index 3f25b258..e84f695d 100755
--- a/test/modtest_d/devtools.py
+++ b/test/modtest_d/devtools.py
@@ -70,8 +70,10 @@ class unit_tests:
 
 	def stack_trace(self, name, ut):
 		print_hdr('stack trace')
-		with open(os.devnull, 'w') as fh:
-			print_stack_trace('Test', fh_list=[fh], trim=0)
+		print_stack_trace('Test', trim=0)
+		print_stack_trace('Test2', trim=2)
+		with open(f'devtools.trace.{os.getpid()}', 'r') as fh:
+			assert len([l for l in fh if l.startswith('STACK TRACE')]) == 2
 		return True
 
 	def obj_pmsg(self, name, ut):