0001-fix-perl-522.patch

--- /automake.in	2017-12-18 12:26:59.455263520 +0100
+++ /automake.in	2017-12-18 12:27:21.228596603 +0100
@@ -4110,7 +4110,7 @@
 sub substitute_ac_subst_variables ($)
 {
   my ($text) = @_;
-  $text =~ s/\${([^ \t=:+{}]+)}/&substitute_ac_subst_variables_worker ($1)/ge;
+  $text =~ s/\$[{]([^ \t=:+{}]+)}/substitute_ac_subst_variables_worker ($1)/ge;
   return $text;
 }