bpo-36254: Fix invalid uses of %d in format strings in C. (GH-12264)
diff --git a/Python/pyarena.c b/Python/pyarena.c
index abb5729..aefb787 100644
--- a/Python/pyarena.c
+++ b/Python/pyarena.c
@@ -160,7 +160,7 @@
#if defined(Py_DEBUG)
/*
fprintf(stderr,
- "alloc=%d size=%d blocks=%d block_size=%d big=%d objects=%d\n",
+ "alloc=%zu size=%zu blocks=%zu block_size=%zu big=%zu objects=%zu\n",
arena->total_allocs, arena->total_size, arena->total_blocks,
arena->total_block_size, arena->total_big_blocks,
PyList_Size(arena->a_objects));