diff --git a/bootstrap b/bootstrap
index fef3cbc..19f9424 100755
--- a/bootstrap
+++ b/bootstrap
@@ -3,9 +3,9 @@
 
 # Bootstrap this package from checked-out sources.
 
-scriptversion=2024-07-04.10; # UTC
+scriptversion=2025-06-10.02; # UTC
 
-# Copyright (C) 2003-2025 Free Software Foundation, Inc.
+# Copyright (C) 2003-2026 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
@@ -37,9 +37,9 @@ medir=`dirname "$me"`
 
 # A library of shell functions for autopull.sh, autogen.sh, and bootstrap.
 
-scriptlibversion=2025-02-16.12; # UTC
+scriptlibversion=2025-12-04.19; # UTC
 
-# Copyright (C) 2003-2025 Free Software Foundation, Inc.
+# Copyright (C) 2003-2026 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
@@ -72,7 +72,7 @@ export LC_ALL
 # Honor $PERL, but work even if there is none.
 PERL="${PERL-perl}"
 
-default_gnulib_url=https://git.savannah.gnu.org/git/gnulib.git
+default_gnulib_url=https://https.git.savannah.gnu.org/git/gnulib.git
 
 # Copyright year, for the --version output.
 copyright_year=`echo "$scriptlibversion" | sed -e 's/[^0-9].*//'`
@@ -861,7 +861,8 @@ autopull()
     elif check_exists git-merge-changelog; then
       echo "$0: initializing git-merge-changelog driver"
       git config merge.merge-changelog.name 'GNU-style ChangeLog merge driver'
-      git config merge.merge-changelog.driver 'git-merge-changelog %O %A %B'
+      git config merge.merge-changelog.driver \
+          'git-merge-changelog %O %A %B "%Y"'
     else
       echo "$0: consider installing git-merge-changelog from gnulib"
     fi
@@ -1337,7 +1338,7 @@ autogen()
 
   # Invoke autoreconf with --force --install to ensure upgrades of tools
   # such as ylwrap.
-  AUTORECONFFLAGS="--verbose --install --force -I $m4_base $ACLOCAL_FLAGS"
+  AUTORECONFFLAGS="--verbose --install --force $ACLOCAL_FLAGS"
   AUTORECONFFLAGS="$AUTORECONFFLAGS --no-recursive"
 
   # Tell autoreconf not to invoke autopoint or libtoolize; they were run above.
@@ -1413,7 +1414,7 @@ autogen()
 # Local Variables:
 # eval: (add-hook 'before-save-hook 'time-stamp nil t)
 # time-stamp-start: "scriptlibversion="
-# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-format: "%Y-%02m-%02d.%02H"
 # time-stamp-time-zone: "UTC0"
 # time-stamp-end: "; # UTC"
 # End:
@@ -1624,7 +1625,7 @@ fi
 # Local Variables:
 # eval: (add-hook 'before-save-hook 'time-stamp nil t)
 # time-stamp-start: "scriptversion="
-# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-format: "%Y-%02m-%02d.%02H"
 # time-stamp-time-zone: "UTC0"
 # time-stamp-end: "; # UTC"
 # End:
diff --git a/gnulib b/gnulib
index 14dd80d..4f6ac2c 160000
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 14dd80dba2d40e608492f0acbec6a90f6bf3877d
+Subproject commit 4f6ac2c3c689cd7312b5f9da97791b14bbc2ee53