$NetBSD: patch-Makefile,v 1.1 2020/03/27 16:34:57 gutteridge Exp $

Fix non-portable test expression.

--- Makefile.orig	2018-07-30 16:05:13.000000000 +0000
+++ Makefile
@@ -74,7 +74,7 @@ valgrind: build $(PYTHON_SUPP)
 	    $(PYTHON) setup.py test
 
 	@grep -A7 "blocks are definitely lost" build/valgrind.log; \
-	if [ $$? == 0 ]; then \
+	if [ $$? = 0 ]; then \
 	    echo "Found definitive leak, see build/valgrind.log"; \
 	    exit 1; \
 	fi