--- /dev/null
+From 13f00eb4493c217269b76614759e452d8302955e Mon Sep 17 00:00:00 2001
+From: Paul Eggert <eggert@cs.ucla.edu>
+Date: Thu, 31 Mar 2016 16:35:29 -0700
+Subject: [PATCH] automake: port to Perl 5.22 and later
+
+Without this change, Perl 5.22 complains "Unescaped left brace in
+regex is deprecated" and this is planned to become a hard error in
+Perl 5.26. See:
+http://search.cpan.org/dist/perl-5.22.0/pod/perldelta.pod#A_literal_%22{%22_should_now_be_escaped_in_a_pattern
+* bin/automake.in (substitute_ac_subst_variables): Escape left brace.
+
+[Backported from:
+ http://git.savannah.gnu.org/cgit/automake.git/commit/?id=13f00eb4493c217269b76614759e452d8302955e]
+Signed-off-by: Adam Duskett <aduskett@gmail.com>
+---
+ bin/automake.in | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/bin/automake.in b/bin/automake.in
+index a3a0aa3..2c8f31e 100644
+--- a/bin/automake.in
++++ b/bin/automake.in
+@@ -3878,7 +3878,7 @@ sub substitute_ac_subst_variables_worker
+ 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;
+ }
+
+--
+2.7.4
+