diff -u -r ../flex-2.6.4/Makefile.in ./Makefile.in
--- ../flex-2.6.4/Makefile.in	2017-05-06 16:49:09.000000000 +0200
+++ ./Makefile.in	2018-04-29 23:46:48.128733975 +0200
@@ -453,7 +453,6 @@
 	doc \
 	examples \
 	po \
-	tests \
 	tools
 
 all: all-recursive