--- swig/perl/GNUmakefile.old	2019-09-02 16:37:34.566311857 +0100
+++ swig/perl/GNUmakefile	2019-09-02 16:38:36.695697656 +0100
@@ -64,3 +64,5 @@
 
 .FORCE:
 	perl parse-for-doxygen.pl > all.pm; doxygen; rm -f all.pm
+
+.PHONY: generate