diff --git a/bootstrap b/bootstrap
line changes: +20/-6
index 5b08e7e..5f1b1b7
--- a/bootstrap
+++ b/bootstrap

@@ -1,10 +1,10 @@
 #! /bin/sh
 # Print a version string.
-scriptversion=2019-01-04.17; # UTC
+scriptversion=2020-11-18.17; # UTC
 
 # Bootstrap this package from checked-out sources.
 
-# Copyright (C) 2003-2019 Free Software Foundation, Inc.
+# Copyright (C) 2003-2020 Free Software Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

@@ -71,7 +71,9 @@ Options:
  --no-git                 do not use git to update gnulib.  Requires that
                           --gnulib-srcdir point to a correct gnulib snapshot
  --skip-po                do not download po files
-
+EOF
+  bootstrap_print_option_usage_hook
+  cat <<EOF
 If the file $me.conf exists in the same directory as this script, its
 contents are read as shell variables to configure the bootstrap.
 

@@ -154,6 +156,18 @@ gnulib_files=
 : ${AUTOPOINT=autopoint}
 : ${AUTORECONF=autoreconf}
 
+# A function to be called for each unrecognized option.  Returns 0 if
+# the option in $1 has been processed by the function.  Returns 1 if
+# the option has not been processed by the function.  Override it via
+# your own definition in bootstrap.conf
+
+bootstrap_option_hook() { return 1; }
+
+# A function to be called in order to print the --help information
+# corresponding to user-defined command-line options.
+
+bootstrap_print_option_usage_hook() { :; }
+
 # A function to be called right after gnulib-tool is run.
 # Override it via your own definition in bootstrap.conf.
 bootstrap_post_import_hook() { :; }

@@ -166,7 +180,7 @@ bootstrap_epilogue() { :; }
 # specified directory.  Fill in the first %s with the destination
 # directory and the second with the domain name.
 po_download_command_format=\
-"wget --mirror --level=1 -nd -q -A.po -P '%s' \
+"wget --mirror --level=1 -nd -nv -A.po -P '%s' \
  https://translationproject.org/latest/%s/"
 
 # Prefer a non-empty tarname (4th argument of AC_INIT if given), else

@@ -335,7 +349,7 @@ do
   --no-git)
     use_git=false;;
   *)
-    die "$option: unknown option";;
+    bootstrap_option_hook $option || die "$option: unknown option";;
   esac
 done
 

@@ -970,7 +984,7 @@ bootstrap_post_import_hook \
 # Uninitialized submodules are listed with an initial dash.
 if $use_git && git submodule | grep '^-' >/dev/null; then
   die "some git submodules are not initialized. "     \
-      "Run 'git submodule init' and bootstrap again."
+      "Run 'git submodule update --init' and bootstrap again."
 fi
 
 # Remove any dangling symlink matching "*.m4" or "*.[ch]" in some

diff --git a/configure.ac b/configure.ac
line changes: +1/-1
index d5f668d..6d52c41
--- a/configure.ac
+++ b/configure.ac

@@ -24,7 +24,7 @@ AM_INIT_AUTOMAKE([
 ])
 
 dnl Minimum Autoconf version required.
-AC_PREREQ([2.63])
+AC_PREREQ([2.64])
 
 dnl Where to generate output; srcdir location.
 AC_CONFIG_HEADERS([config.h:config.in])dnl Keep filename to 8.3 for MS-DOS.

diff --git a/gnulib b/gnulib
line changes: +1/-1
index 5ddb2f9..bbaba6c
--- a/gnulib
+++ b/gnulib

@@ -1 +1 @@
-Subproject commit 5ddb2f9d460a85a56f1c47c57c48395ccdc4ea12
+Subproject commit bbaba6ce591b94c8fca491f4ef019187cd171521