cext: cast s# arguments of Py_BuildValue() to Py_ssize_t The doc doesn't state that "s#" of Py_BuildValue() is controlled by PY_SSIZE_T_CLEAN (unlike the one for PyArg_ParseTuple()), but actually it's switched to Py_ssize_t. https://docs.python.org/2/c-api/arg.html#c.Py_BuildValue https://github.com/python/cpython/blob/2.7/Python/modsupport.c#L432 Follow up for b01bbb8ff1f2 and 896b19d12c08.

--- a/mercurial/cext/parsers.c	Mon Apr 08 10:52:04 2019 -0400
+++ b/mercurial/cext/parsers.c	Tue Apr 09 21:59:37 2019 +0900
@@ -184,7 +184,8 @@
 		goto quit;
 	}
 
-	parents = Py_BuildValue(PY23("s#s#", "y#y#"), str, 20, str + 20, 20);
+	parents = Py_BuildValue(PY23("s#s#", "y#y#"), str, (Py_ssize_t)20,
+	                        str + 20, (Py_ssize_t)20);
 	if (!parents) {
 		goto quit;
 	}