[Bug bootstrap/82856] [8 Regression] --enable-maintainter-mode broken by automake failure

[tkoenig at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82856

--- Comment #3 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
FWITW, the patch to automake

--- automake-1.11.orig  2017-11-06 21:47:27.451349052 +0100
+++ automake    2017-11-06 21:48:29.882102274 +0100
@@ -4156,7 +4156,7 @@
 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;
 }

seems to fix the issue for me.