Properly update if usvg-processor changed

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/Makefile b/Makefile
index 6c7fab67bd4e22be3d8521dcd844048a822de7c1..d7eaf616431e87dffcd8b5ae171a769d9b1eb8fe 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -36,7 +36,9 @@ endif
 
 include $(wildcard library/*/files.make)
 
-LIBRARY_PROCESS_SVG = ./usvg-processor $@ $^ '$(USVG)'
+USVG_PROCESSOR = usvg-processor
+LIBRARY_PROCESS_SVG = ./$(USVG_PROCESSOR) $@ $(filter-out $(USVG_PROCESSOR),$^) '$(USVG)'
+$(LIBRARY_FILES): $(USVG_PROCESSOR)
 
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