--- Makefile.am.orig	2021-06-09 09:17:54 UTC
+++ Makefile.am
@@ -5,10 +5,11 @@ libpolys gfanlib IntegerProgramming \
 kernel Singular \
 dox emacs redhat desktop
 
-DIST_SUBDIRS = $(SUBDIRS) doc
-if ENABLE_DOC_BUILD
-SUBDIRS += doc
-endif
+# doc does not exist any longer
+#DIST_SUBDIRS = $(SUBDIRS) doc
+#if ENABLE_DOC_BUILD
+#SUBDIRS += doc
+#endif
 
 EXTRA_DIST = README README.md README.pkg autogen.sh doxy redhat/singular.spec.in GPL2 GPL3