diff -Nru orig/vdiffr/src/Makevars.ucrt patched/vdiffr/src/Makevars.ucrt
--- orig/vdiffr/src/Makevars.ucrt	1969-12-31 16:00:00.000000000 -0800
+++ patched/vdiffr/src/Makevars.ucrt	2021-06-17 03:36:39.148120100 -0700
@@ -0,0 +1,8 @@
+CXX_STD = CXX11
+
+PKG_LIBS = -lpng -lz
+
+all: clean 
+
+clean:
+	rm -f $(OBJECTS)