Use %zd instead of %i as format character (in call to PyErr_Format) for
Py_ssize_t argument.
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index f6996c7..292d02b 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -4219,7 +4219,7 @@
/* Convert item to Unicode. */
if (! PyUnicode_Check(item) && ! PyString_Check(item)) {
PyErr_Format(PyExc_TypeError,
- "sequence item %i: expected string or Unicode,"
+ "sequence item %zd: expected string or Unicode,"
" %.80s found",
i, item->ob_type->tp_name);
goto onError;