Makefile.PL: add update-copyrights target

It might save me a few cycles every year to not have to
scroll through git history to see how it's run.

diff --git a/Makefile.PL b/Makefile.PL
index 924e8dfd2b00cd4064247e23437699413a367717..613a72ae3d9a535cae80b125d2cd2d4c29ac8e67 100644 (file)
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -1,5 +1,5 @@
 #!/usr/bin/perl -w
-# Copyright (C) 2013-2020 all contributors <meta@public-inbox.org>
+# Copyright (C) 2013-2021 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 use strict;
 use ExtUtils::MakeMaker;
@@ -234,5 +234,11 @@ symlink-install :
        for x in \$(EXE_FILES); do \\
                ln -sf "\$\$lei" \$\$(basename "\$\$x"); \\
        done
+
+update-copyrights :
+       \@case '\$(GNULIB_PATH)' in '') echo >&2 GNULIB_PATH unset; false;; esac
+       git ls-files | UPDATE_COPYRIGHT_HOLDER='all contributors' \\
+               UPDATE_COPYRIGHT_USE_INTERVALS=2 \\
+               xargs \$(GNULIB_PATH)/build-aux/update-copyright
 EOF
 }