From d74dff7e48432bb76240fc1f970e127adbe2a4e2 Mon Sep 17 00:00:00 2001
From: Doug Torrance <dtorrance@piedmont.edu>
Date: Sat, 28 Feb 2026 13:53:53 -0500
Subject: [PATCH] Set argtypes for sprintf from ctypes

Needed on some architectures (see the "Calling variadic functions" in
the ctypes documentation).
---
 mpmath/tests/test_format.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mpmath/tests/test_format.py b/mpmath/tests/test_format.py
index 00ac61f2..896c003c 100644
--- a/mpmath/tests/test_format.py
+++ b/mpmath/tests/test_format.py
@@ -864,6 +864,7 @@ except OSError:
 def float_print(d, i):
     fmt = "%." + str(i) + "a\n"
     a = ctypes.create_string_buffer(256)
+    libc.sprintf.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
     libc.sprintf(a, bytes(fmt, 'utf-8'), ctypes.c_double(d))
     return a.raw.decode('utf-8').split("\n")[0]